Toward a comprehensive hypothesis of oxygen-evolution reaction in the presence of iron and gold

This study investigates the effects of Fe on the oxygen-evolution reaction(OER)in the presence of Au.Two distinct areas of OER were identified:the first associated with Fe sites at low overpotential(~330 mV),and the second with Au sites at high overpotential(~870 mV).Various factors such as surface Fe concentration,electrochemical method,scan rate,potential range,concentration,method of adding K_(2)Fe O_(4),nature of Fe,and temperature were varied to observe diverse behaviors during OER for Fe O_(x)H_(y)/Au.Trace amounts of Fe ions had a significant impact on OER,reaching a saturation point where the activity did not increase further.Strong electronic interaction between Fe and Au ions was indicated by X-ray photoelectron spectroscopy(XPS)and electron paramagnetic resonance(EPR)analyses.In situ visible spectroscopy confirmed the formation of Fe O_(4)^(2-)during OER.In situ Mossbauer and surfaceenhanced Raman spectroscopy(SERS)analyses suggest the involvement of Fe-based species as intermediates during the rate-determining step of OER.A lattice OER mechanism based on Fe O_(x)H_(y)was proposed for operation at low overpotentials.Density functional theory(DFT)calculations revealed that Fe oxide,Fe-oxide clusters,and Fe doping on the Au foil exhibited different activities and stabilities during OER.The study provides insights into the interplay between Fe and Au in OER,advancing the understanding of OER mechanisms and offering implications for the design of efficient electrocatalytic systems.

Robust GEFA Assessment of Climate Feedback to SST EOF Modes

Atmospheric response to SST variability was estimated using generalized equilibrium feedback analysis （GEFA） in the SST EOF space with synthesis data from an idealized climate model. Results show that the GEFA atmospheric response to the leading SST EOF modes is much more accurate and robust than the GEFA feedback matrix in physical space. Therefore, GEFA provides a practical method for assessing atmospheric response to large-scale SST anomalies in terms of the leading EOFs.

Parameterization of Sheared Entrainment in a Well-Developed CBL.Part I:Evaluation of the Scheme through Large-Eddy Simulations

The entrainment flux ratio Ae and the inversion layer （IL） thickness are two key parameters in a mixed layer model. Ae is defined as the ratio of the entrainment heat flux at the mixed layer top to the surface heat flux. The IL is the layer between the mixed layer and the free atmosphere. In this study, a parameterization of Ae is derived from the TKE budget in the first- order model for a well-developed CBL under the condition of linearly sheared geostrophic velocity with a zero value at the surface. It is also appropriate for a CBL under the condition of geostrophic velocity remaining constant with height. LESs are conducted under the above two conditions to determine the coefficients in the parameterization scheme. Results suggest that about 43% of the shear-produced TKE in the IL is available for entrainment, while the shear-produced TKE in the mixed layer and surface layer have little effect on entrainment. Based on this scheme, a new scale of convective turbulence velocity is proposed and applied to parameterize the IL thickness, The LES outputs for the CBLs under the condition of linearly sheared geostrophic velocity with a non-zero surface value are used to verify the performance of the parameterization scheme. It is found that the parameterized Ae and IL thickness agree well with the LES outputs.

Parameterization of Sheared Entrainment in a Well-developed CBL.PartⅡ:A Simple Model for Predicting the Growth Rate of the CBL

Following the parameterization of sheared entrainment obtained in the companion paper, Liu et al. （2016）, the present study aims to further investigate the characteristics of entrainment, and develop a simple model for predicting the growth rate of a well-developed and sheared CBL. The relative stratification, defined as the ratio of the stratification in the free atmosphere to that in the entrainment zone, is found to be a function of entrainment flux ratio （Ae）. This leads to a simple expression of the entrainment rate, in which Ae needs to be parameterized. According to the results in Liu et al. （2016）, Ae can be simply expressed as the ratio of the convective velocity scale in the sheared CBL to that in the shear-free CBL. The parameterization of the convective velocity scale in the sheared CBL is obtained by analytically solving the bulk model with several assumptions and approximations. Results indicate that the entrainment process is influenced by the dynamic effect, the interaction between mean shear and environmental stratification, and one other term that includes the Coriolis effect. These three parameterizations constitute a simple model for predicting the growth rate of a well-developed and sheared CBL. This model is validated by outputs of LESs, and the results show that it performs satisfactorily. Compared with bulk models, this model does not need to solve a set of equations for the CBL. It is more convenient to apply in numerical models.

CLIMATE WARMING IN GUANGDONG PROVINCE AND ITS INFLUENCES ON AGRICULTURE AND COUNTER MEASURES

Climate changes in Guangdong are studied based on temperature data of 86 meteorological stations in Guangdong Province during 1961 – 2000, temperature data in Guangzhou during 1908 – 2002, and sea level data in the South China Sea during 1958 – 2001. Significant climate warming and sea level rise in Guangdong is demonstrated. Possible influences of climate warming on agriculture in Guangdong are discussed in terms of thermal resources, crop and breed layout, crop yield, diseases, insect pests and weeds as well as agrometeorological disasters, etc. In the final part, agricultural strategies of mitigating and adapting to the climate changes are given.

Long-term observation of air pollution-weather/climate interactions at the SORPES station： a review and outlook

This work presents an overall introduction to the Station for Observing Regional Processes of the EarthSystem - SORPES in Nanjing, East China, and gives an overview about main scientific findings instudies of air pollution-weather/climate interactions obtained since 2011. The main results summarizedin this paper include overall characteristics of trace gases and aerosols, chemical transformationmechanisms for secondary pollutants like O3, HONO andsecondary ingrganic aerosols, and the airpollution- weather/climate interactions and feedbacks in mixed air pollution plumes from sources likefossil fuel combustion, biomass burning and dust storms. The future outlook of the development plan on instrumentation, networking and data-sharing for the SORPES station is also discussed.

疫情期间全球空气质量变化:臭氧响应的区域间差异

疫情期间全球各地一次排放大幅削减,而臭氧等二次污染的响应则存在着区域间差异.结合地面和卫星观测发现,同在氮氧化物大幅下降的情况下,臭氧在东亚和欧洲呈现出可达14ppb的上升信号,而北美则下降为主(约2–4ppb).我们结合气象分析和臭氧敏感性进一步讨论了臭氧响应差异性的原因,一方面受臭氧与前体物间关系的影响;另一方面来自于气象,尤其是温度.研究明晰了人为排放,化学和气象三者的内在关联,强调了在臭氧控制过程中考虑前体物削减和气象条件协同的重要性.

Response of organic aerosol characteristics to emission reduction in Yangtze River Delta region

Organic aerosol(OA)is a major component of atmospheric particulate matter(PM)with complex composition and formation processes influenced by various factors.Emission reduction can alter both precursors and oxidants which further affects secondary OA formation.Here we provide an observational analysis of secondary OA(SOA)variation properties in Yangtze River Delta(YRD)of eastern China in response to large scale of emission reduction during Chinese New Year(CNY)holidays from 2015 to 2020,and the COVID-19 pandemic period from January to March,2020.We found a 17%increase of SOA proportion during the COVID lockdown.The relative enrichment of SOA is also found during multi-year CNY holidays with dramatic reduction of anthropogenic emissions.Two types of oxygenated OA(OOA)influenced by mixed emissions and SOA formation were found to be the dominant components during the lockdown in YRD region.Our results highlight that these emission-reduction-induced changes in organic aerosol need to be considered in the future to optimize air pollution control measures.

Study on the Overfitting of the Artificial Neural Network Forecasting Model

Because of overfitting and the improvement of generalization capability (GC)available in the construction of forecasting models using artificial neural network (ANN), a newmethod is proposed for model establishment by means of making a low-dimension ANN learning matrixthrough principal component analysis (PCA). The results show that the PC A is able to construct anANN model without the need of finding an optimal structure with the appropriate number ofhidden-layer nodes, thus avoids overfitting by condensing forecasting information, reducingdimension and removing noise, and GC is greatly raised compared to the traditional ANN and stepwiseregression techniques for model establishment.

Distribution characteristics of soil organic carbon and nitrogen in farmland and adjacent natural grassland in Tibet

Land-use significantly affects soil organic carbon(SOC)and nitrogen cycling,eventually leading to global climate change.The cold and arid climate conditions in Tibet are not conducive to transformation of SOC and nitrogen.Hence,research on SOC and nitrogen distribution under different land-use patterns in Tibet is an important basis to assess the soil carbon and nitrogen potential in the land ecosystem of this area.This study aims to explain the effects of two land-use patterns,namely,farmland and grassland,on SOC and nitrogen contents in the cold regions of Tibet.This study also seeks to provide a scientific basis for the agricultural and grass production system.To achieve these goals,the changing features of total nitrogen(TN),mineralized nitrogen(nitrate nitrogen(NN)and ammonium nitrogen(AN)),and SOC were analyzed in different soil depths(0-5,5-10,10-20,20-30,30-40,and 40-50 cm)in farmland and adjacent natural grassland.The differences in carbon and nitrogen contents between the farmland and grassland of the main agricultural area of Tibet were determined through combined field survey and lab analysis.Results showed that the contents of SOC,TN and mineralized nitrogen in the grassland and farmland decreased with increasing soil depth mainly in the surface with depth of 0-20 cm.The effects of the different land-use patterns on the contents of SOC and TN were primarily evident in the 0-10 cm surface layer.The contents of SOC and TN in the farmland were significantly lower than those in the grassland,with mean reduction by 28.36%for SOC and 20.76%for TN.When the soil layer is deeper than 10 cm,the contents of SOC and TN in the farmland were greater than those in the grassland.This finding indicated that the transformation from grassland to farmland in Tibet mainly influenced the SOC and TN in the 0-10 cm surface layer.Moreover,the results showed that the increment of carbon in the deep soil layers of the farmland partially offsets the SOC loss from the surface because of cultivation.The ratio of mineralized nitrogen to TN in the farmland was significantly higher than that in the grassland(p<0.001).Mineralized nitrogen in the farmland mainly existed in the form of NN,with a mean content of 2.7%in the 0-50 cm surface layer.By contrast,the difference in the ratio of AN to TN between the grassland and farmland was not significant.The results revealed that the land-use pattern in extremely cold agricultural areas mainly affects the contents of SOC and nitrogen in the 0-10 cm surface layer,and agricultural management is beneficial in increasing the SOC content in the deeper layers.

Observational study of land-atmosphere turbulent flux exchange over complex underlying surfaces in urban and suburban areas

Based on observation data from urban observation stations in Nanjing and Suzhou at two heights in the roughness sublayer above the canopy and observation data at three heights in the SORPES station at the Xianlin Campus of Nanjing University in a suburban area,the of land-atmosphere turbulent flux exchange and the energy balance over complex underlying surfaces were analyzed.The results indicated that in the roughness sublayer above the canopy,the nearsurface momentum flux,sensible heat flux,and latent heat flux increase with height,and the observation value of the surface albedo increases with height.However,the observation value of the net radiation decreases with height,thus resulting in a change in the urban surface energy budget with height.At the SORPES station in the Xianlin Campus of Nanjing University located in a hilly area,the momentum flux,sensible heat flux,and latent heat flux of the ground observation field significantly differed from those of the two heights on the tower,while the two heights on the tower were extremely close.These results indicate that the flux observation over the complex underlying surface exhibits adequate local only when it is conducted at a higher altitude above the ground.The turbulent flux observation results at a lower altitude in urban areas are underestimated,while the turbulent flux observation results near the surface produce a large deviation over the underlying hilly complex.

Atmospheric gaseous organic acids in winter in a rural site of the North China Plain

Organic acids are important contributors to the acidity of atmospheric precipitation,but their existence in the Chinese atmosphere is largely unclear.In this study,twelve atmospheric gaseous organic acids,including C_(1)-C_(9) alkanoic acids,methacrylic acid,pyruvic acid,and benzoic acid,were observed in the suburb of Wangdu,Hebei Province,a typical rural site in the northern China plain from 16^(th) December,2018 to 22^(nd) January,2019,using a Vocus■ Proton-Transfer-Reaction time-of-flight mass spectrometer(Vocus PTR-ToF).The quantification of C_(2)-C_(4) alkanoic acids by the Vocus PTR-ToF was calibrated according to the titration of a NaOH solution by C_(2)-C_(4) alkanoic acids from home-made permeation sources,and the other organic acids except for formic acid were quantified based on the k_(cap)-sensitivity linearity in the Vocus PTR-ToF,whereas formic acid was not quantified because our instrument setting led to a significant underestimation in its concentration.The average total concentration of eleven gaseous organic acids was 6.96±5.20 ppbv(parts per billion by volume).The average concentration of acetic acid was the highest(3.86±3.00 ppbv),followed by propanoic acid,butyric acid,and methacrylic acid.Domestic straw burning was likely the dominant source of the observed gaseous organic acids according to the good correlations between acetonitrile and organic acids and between particulate K+and organic acids,and traffic emissions could also have contributed.During episodes with continuously high concentrations of organic acids,short-distance transport dominated in Wangdu according to the backward trajectory analysis.Baoding,Shijiazhuang,and Hengshui areas were the main source areas based on potential source contribution function and concentration weighing track analysis.

Numerical study of the effects of Planetary Boundary Layer structure on the pollutant dispersion within built-up areas

The effects of different Planetary Boundary Layer（PBL） structures on pollutant dispersion processes within two idealized street canyon configurations and a realistic urban area were numerically examined by a Computational Fluid Dynamics（CFD） model. The boundary conditions of different PBL structures/conditions were provided by simulations of the Weather Researching and Forecasting model. The simulated results of the idealized 2D and 3D street canyon experiments showed that the increment of PBL instability favored the downward transport of momentum from the upper flow above the roof to the pedestrian level within the street canyon. As a result, the flow and turbulent fields within the street canyon under the more unstable PBL condition are stronger. Therefore, more pollutants within the street canyon would be removed by the stronger advection and turbulent diffusion processes under the unstable PBL condition. On the contrary, more pollutants would be concentrated in the street canyon under the stable PBL condition. In addition, the simulations of the realistic building cluster experiments showed that the density of buildings was a crucial factor determining the dynamic effects of the PBL structure on the flow patterns. The momentum field within a denser building configuration was mostly transported from the upper flow, and was more sensitive to the PBL structures than that of the sparser building configuration. Finally, it was recommended to use the Mellor-Yamada-Nakanishi-Niino（MYNN） PBL scheme, which can explicitly output the needed turbulent variables, to provide the boundary conditions to the CFD simulation.

The failed invasion of Harmonia axyridis in the Azores, Portugal: Climatic restriction or wrong population origin?

We tested two questions:(i)whether the climatic conditions of the Azorean Islands in Portugal may have restricted the invasion of Harmonia axyridis across this archipelago and(ii)determine what population of this species could have a higher probability of invading the islands.We used MaxEnt to project the climate requirements of different H.axyridis populations from three regions of the world,and the potential global niche of the species in the Azorean islands.Then we assessed the suitability of the islands for each of the three H.axyridis populations and global potential niche through histograms analysis,Principal Component Analysis(PCA)of climate variables,and a variable-by-variable assessment of the suitability response curves compared with the climatic conditions of the Azores.Climatic conditions of the Azores are less suitable for the U.S.and native Asian populations of H.axyridis,and more suitable for European populations and the global potential niche.The PCA showed that the climatic conditions of the islands differed from the climatic requirements of H.axyridis.This difference is mainly explained by precipitation of the wettest month,isothermality,and the minimum temperature of the coldest month.We concluded that the climatic conditions of the Azores could have influenced the establishment and spread of H.axyridis on these islands from Europe.Our results showed that abiotic resistance represented by the climate of the potentially colonizable zones could hinder the establishment of invasive insects,but it could vary depending of the origin of the colonizing population.

青藏高原新能源助力中国“碳中和”战略

作为世界屋脊、亚洲水塔和地球第三极,青藏高原约占中国国土面积的25%,而其光伏发电和风电的潜力分别占全国总潜力的45.6%和38.5%左右.青藏高原巨大的清洁能源资源有望为中国2060年的“碳中和”目标作出重要贡献.尽管有一些研究尝试评估青藏高原清洁能源潜力,但由于使用了低精度、粗分辨率的太阳辐射和风速数据,其评估结果具有较大的不确定性.本研究利用更高精度和分辨率的太阳辐射和风速数据以及更符合青藏高原实际的生态约束因子,精细化定量评估了青藏高原光伏发电和风电技术可开发潜力.研究结果表明:(1)青藏高原在技术上可实现的光伏发电和风电潜力超过10.4 PW h/a,可满足中国2030年的总电力消耗,并可以避免8.75 Gt的CO_(2)排放;(2)柴达木盆地适合建立国家清洁能源基地,每年可产生超过6.6 PW h的清洁电力.

Electric vehicle adoption delivers public health and environmental benefits

Large-scale electric vehicle(EV)deployment powered by renewable electricity has the potential to drastically change the environmental impacts of road transportation.The transportation sector is a major contributor to global greenhouse gas(GHG)emissions[1,2],air pollution,and related health impacts[3].Renewable-powered EVs substantially decrease fossil fuel consumption and are a pivotal technology to reduce transportation’s climate burden while also substantially improving air quality and public health.However.

中国生产型和消费型二氧化碳排放清单分析（英文）

中国作为最大的发展中国家,已经成为二氧化碳第一排放大国,因此,国际社会开始敦促中国在后京都时期承担更多减排责任。现阶段,《联合国气候变化框架条约》使用生产型二氧化碳排放清单,这就意味着它将减排责任分配给了污染制造者。本文比较并分析了中国的生产型和消费型二氧化碳排放清单,并认为消费型的二氧化碳排放清单更为公平合理,产品的消费者应该为他们所购买的产品中隐含的碳排放付费。此外,为了考虑公平问题,政府应采取全面的经济政策和行政手段扶持经济落后的省份进行减排。

平流层向对流层传输过程对中国东部夏季地表臭氧的影响

基于最新的ERA5再分析资料、IAGOS飞机航测数据、地表观测数据以及模式模拟研究发现,平流层向对流层的传输(STT)对中国东部地区夏季的臭氧污染具有重要作用.一次典型STT过程表明, STT对南京夏季地表臭氧的贡献约为10 ppbv.根据2011~2017年的统计数据,我们发现夏季在南亚高压和副热带高压之间存在一个气旋性的通道,将平流层空气向对流层输送,从而影响中国东部地区近地面臭氧.我们的结果为中国东部地表臭氧的预测和控制提供了重要信息.

气溶胶:导致全球天气预报模式中气温预报偏差的关键因素

天气预报与人们的日常生活息息相关.尽管过去几十年大气动力模式和高性能计算技术快速发展,当前天气预报的准确度在部分地区依然存在较大差异.本研究系统比较了全球3年的短期(1-5天)预报和同化气象观测的再分析资料,发现气温预报偏差和大气中的气溶胶存在显著关联.在人为或自然排放密集的地区和季节(如化石燃料燃烧排放量巨大的中国和印度、生物质燃烧频发的南非和亚马逊等),气温预报往往存在更大的偏差,且随着预报时长而显著放大.虽然与空气污染相关的大气化学及气溶胶的理化过程在气候模式中已经普遍得到显式的表达和解析,但在天气预报模式中尚未引起足够的重视.本文以直接的"观测"证据揭示了空气污染对全球天气预报的影响,进一步证明了"化学天气"及理化过程相互作用研究的重要性.

Simulating Aerosol Size Distribution and Mass Concentration with Simultaneous Nucleation,Condensation/Coagulation, and Deposition with the GRAPES–CUACE

A coupled aerosol–cloud model is essential for investigating the formation of haze and fog and the interaction of aerosols with clouds and precipitation. One of the key tasks of such a model is to produce correct mass and number size distributions of aerosols. In this paper, a parameterization scheme for aerosol size distribution in initial emission,which took into account the measured mass and number size distributions of aerosols, was developed in the GRAPES–CUACE [Global/Regional Assimilation and Pr Ediction System–China Meteorological Administration（CMA） Unified Atmospheric Chemistry Environment model]—an online chemical weather forecast system that contains microphysical processes and emission, transport, and chemical conversion of sectional multi-component aerosols. In addition, the competitive mechanism between nucleation and condensation for secondary aerosol formation was improved, and the dry deposition was also modified to be in consistent with the real depositing length. Based on the above improvements, the GRAPES–CUACE simulations were verified against observational data during 1–31 January 2013, when a series of heavy regional haze–fog events occurred in eastern China. The results show that the aerosol number size distribution from the improved experiment was much closer to the observation, whereas in the old experiment the number concentration was higher in the nucleation mode and lower in the accumulation mode. Meanwhile, the errors in aerosol number size distribution as diagnosed by its sectional mass size distribution were also reduced. Moreover, simulations of organic carbon, sulfate, and other aerosol components were improved and the overestimation as well as underestimation of PM2.5 concentration in eastern China was significantly reduced,leading to increased correlation coefficient between simulated and observed PM2.5 by more than 70%. In the remote areas where bad simulation results were produced previously, the correlation coefficient grew from 0.35 to 0.61, and the mean mass concentration went up from 43% to 87.5% of the observed value. Thus, the simulation of particulate matters in these areas has been improved considerably.