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Attribution of Biases of Interhemispheric Temperature Contrast in CMIP6 Models

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Advances in Atmospheric Sciences 2024年第2期41卷 325-340页

作者： Shiyan zhang Yongyun HU Jiankai zhang yan XIA Laboratory for Climate and Ocean-Atmosphere Studies Department of Atmospheric and Oceanic SciencesSchool of PhysicsPeking UniversityBeijing 100871China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China School of Systems Science Beijing Normal UniversityBeijing 100875China

One of the basic characteristics of Earth's modern climate is that the Northern Hemisphere(NH) is climatologically warmer than the Southern Hemisphere(SH). Here, model performances of this basic state are examined using simulation results from 26 CMIP6 models. Results show that the CMIP6 models underestimate the contrast in interhemispheric surface temperatures on average(0.8 K for CMIP6 mean versus 1.4 K for reanalysis data mean), and that there is a large intermodel spread, ranging from -0.7 K to 2.3 K. A box model energy budget analysis shows that the contrast in interhemispheric shortwave absorption at the top of the atmosphere, the contrast in interhemispheric greenhouse trapping, and the crossequatorial northward ocean heat transport, are all underestimated in the multimodel mean. By examining the intermodel spread, we find intermodel biases can be tracked back to biases in midlatitude shortwave cloud forcing in AGCMs. Models with a weaker interhemispheric temperature contrast underestimate the shortwave cloud reflection in the SH but overestimate the shortwave cloud reflection in the NH, which are respectively due to underestimation of the cloud fraction over the SH extratropical ocean and overestimation of the cloud liquid water content over the NH extratropical continents.Models that underestimate the interhemispheric temperature contrast exhibit larger double ITCZ biases, characterized by excessive precipitation in the SH tropics. Although this intermodel spread does not account for the multimodel ensemble mean biases, it highlights that improving cloud simulation in AGCMs is essential for simulating the climate realistically in coupled models.

关键词： interhemispheric temperature contrast energy balance shortwave cloud forcing ITCZ CMIP6 AGCM

Targeting ASIC1a Promotes Neural Progenitor Cell Migration and Neurogenesis in Ischemic Stroke

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Research 2024年第1期2023卷 369-387页

作者： Hongfei ge Tengyuan Zhou Chao zhang Yupeng Cun Weixiang Chen yang yang Qian zhang Huanhuan Li Jun Zhong Xuyang zhang Hua Feng Rong Hu Department of Neurosurgery and Key Laboratory of Neurotrauma Southwest HospitalThird Military Medical University(Army Medical University)400038 ChongqingChina Medical Research Center Southwest HospitalThird Military Medical University(Army Medical University)400038 ChongqingChina Pediatric Research Institute Ministry of Education Key Laboratory of Child Development and DisordersNational Clinical Research Center for Child Health and DisordersChildren’s Hospital of Chongqing Medical University400014 ChongqingChina

Cell replacement therapy using neural progenitor cells(NPCs)has been shown to be an effective treatment for ischemic stroke.However,the therapeutic effect is unsatisfactory due to the imbalanced homeostasis of the local microenvironment after ischemia.Microenvironmental acidosis is a common imbalanced homeostasis in the penumbra and could activate acid-sensing ion channels 1a(ASIC1a),a subunit of proton-gated cation channels following ischemic stroke.However,the role of ASIC1a in NPCs post-ischemia remains elusive.Here,our results indicated that ASIC1a was expressed in NPCs with channel functionality,which could be activated by extracellular acidification.Further evidence revealed that ASIC1a activation inhibited NPC migration and neurogenesis through RhoA signaling-mediated reorganization of filopodia formation,which could be primarily reversed by pharmacological or genetic disruption of ASIC1a.In vivo data showed that the knockout of the ASIC1a gene facilitated NPC migration and neurogenesis in the penumbra to improve behavioral recovery after stroke.

关键词： ASIC1a homeostasis inhibited

Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020

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Chinese geographical Science 2024年第1期34卷 181-194页

作者： ZHU Yuanyuan zhang yan ZHU Xiaohua Key Laboratory of geographic Process Analysis&Simulation Hubei Province Central China Normal UniversityWuhan430079China Institute of geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing100101China

Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern.

关键词： dietary structure structural evolution carbon emission effects carbon neutrality China

Ultrathin Zincophilic Interphase Regulated Electric Double Layer Enabling Highly Stable Aqueous Zinc‑Ion Batteries

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Nano-Micro Letters 2024年第5期16卷 285-299页

作者： Yimei Chen Zhiping Deng Yongxiang Sun Yue Li Hao zhang ge Li Hongbo Zeng Xiaolei Wang Department of Chemical and Materials Engineering University of Alberta9211‑116 Street NWEdmontonAB T6G 1H9Canada Department of Mechanical Engineering University of Alberta9211‑116 Street NWEdmontonAB T6G 1H9Canada

The practical application of aqueous zinc-ion batteries for large-grid scale systems is still hindered by uncontrolled zinc dendrite and side reactions.Regulating the elec-trical double layer via the electrode/electrolyte interface layer is an effective strategy to improve the stability of Zn anodes.Herein,we report an ultrathin zincophilic ZnS layer as a model regu-lator.At a given cycling current,the cell with Zn@ZnS electrode displays a lower potential drop over the Helmholtz layer(stern layer)and a suppressed diffuse layer,indicating the regulated charge distribution and decreased electric double layer repulsion force.Boosted zinc adsorption sites are also expected as proved by the enhanced electric double-layer capacitance.Consequently,the symmetric cell with the ZnS protection layer can stably cycle for around 3,000 h at 1 mA cm^(-2) with a lower overpotential of 25 mV.When coupled with an I2/AC cathode,the cell demonstrates a high rate performance of 160 mAh g^(-1) at 0.1 A g^(-1) and long cycling stability of over 10,000 cycles at 10 A g^(-1).The Zn||MnO_(2) also sustains both high capacity and long cycling stability of 130 mAh g^(-1) after 1,200 cycles at 0.5 A g^(-1).

关键词： Zinc anode Electric double-layer regulation Multifunction SEI layer Inhibited side reactions and dendrite Rapid kinetics

A novel graph oversampling framework for node classification in class-imbalanced graphs

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Science China(Information Sciences) 2024年第6期67卷 214-229页

作者： Riting XIA Chunxu zhang yan zhang Xueyan LIU Bo yanG Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University College of Artificial Intelligence Jilin University College of Computer Science and Technology Jilin University College of Communication Engineering Jilin University

Graph neural network(GNN) is a promising method to analyze graphs. Most existing GNNs adopt the class-balanced assumption, which cannot deal with class-imbalanced graphs well. The oversampling technique is effective in alleviating class-imbalanced problems. However, most graph oversampling methods generate synthetic minority nodes and their edges after applying GNNs. They ignore the problem that the representations of the original and synthetic minority nodes are dominated by majority nodes caused by aggregating neighbor information through GNN before oversampling. In this paper, we propose a novel graph oversampling framework, termed distribution alignment-based oversampling for node classification in classimbalanced graphs(named Graph-DAO). Our framework generates synthetic minority nodes before GNN to avoid the dominance of majority nodes caused by message passing in GNNs. Additionally, we introduce a distribution alignment method based on the sum-product network to learn more information about minority nodes. To our best knowledge, it is the first to use the sum-product network to solve the class-imbalanced problem in node classification. A large number of experiments on four real datasets show that our method achieves the optimal results on the node classification task for class-imbalanced graphs.

关键词： graph neural network class-imbalanced graphs sum-product network oversampling node classification

The structure-directing role of heterologous seeds in the synthesis of zeolite

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Green Energy & Environment 2024年第5期9卷 792-801页

作者： Haoyang zhang Binyu Wang Wenfu yan State Key Laboratory of Inorganic Synthesis&Preparative Chemistry College of ChemistryJilin UniversityChangchun130012China

Zeolites have been widely used as catalysts,ion-exchangers,and adsorbents in chemical industries,detergent industry,steel industry,glass industry,ceramic industry,medical and healthﬁeld,and environmentalﬁeld,and recently applied in energy storage.Seed-assisted synthesis is a very effective approach in promoting the crystallization of zeolites.In some cases,the target zeolite cannot be formed in the absence of seed zeolite.In homologous seed-assisted synthesis,the structure of the seed zeolite is the same to that of the target zeolite,while the structure of the seed zeolite is different to that of the target zeolite in the heterologous seed-assisted synthesis.In this review,we brieﬂy summarized the heterologous seed-assisted syntheses of zeolites and analyzed the structure-directing effect of heterologous seeds and surveyed the“common composite building units(CBUs)hypothesis”and the“common secondary building units(SBUs)hypothesis”.However,both hypotheses cannot explain all observations on the heterologous seed-assisted syntheses.Finally,we proposed that the formation of the target zeolite does need nuclei with the structure of target zeolite and the formation of the nuclei of the target zeolite can be promoted by either the undissolved seed crystals with the same CBUs or SBUs to the target zeolite or by the facilitated appropriate distribution of the speciﬁc building units due to the presence of the heterologous seed that does not have any common CBUs and SBUs with the target zeolite.

关键词： Zeolite Heterologous seed Synthesis Structure-directing effect

Calcium-based polymers for suppression of soil acidification by improving acid-buffering capacity and inhibiting nitrification

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Journal of Environmental Sciences 2024年第5期139卷 138-149页

作者： Fei Kang Yunshan Meng yanning ge Yun zhang Haixiang Gao Xueqin Ren Jie Wang Shuwen Hu Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China Department of Applied Chemistry China Agricultural UniversityBeijing 100193China

Soil acidification is a major threat to agricultural sustainability in tropical and subtropical regions.Biodegradable and environmentally friendly materials,such as calcium lignosulfonate(CaLS),calcium poly(aspartic acid)(PASP-Ca),and calcium polyγ-glutamic acid(γ-PGA-Ca),are known to effectively ameliorate soil acidity.However,their effectiveness in inhibiting soil acidification has not been studied.This study aimed to evaluate the effect of CaLS,PASP-Ca,andγ-PGA-Ca on the resistance of soil toward acidification as directly and indirectly(i.e.,via nitrification)caused by the application of HNO_(3)and urea,respectively.For comparison,Ca(OH)_(2)and lignin were used as the inorganic and organic controls,respectively.Among the materials,γ-PGA-Ca drove the substantial improvements in the pH buffering capacity(pHBC)of the soil and exhibited the greatest potential in inhibiting HNO_(3)-induced soil acidification via protonation of carboxyl,complexing with Al~(3+),and cation exchange processes.Under acidification induced by urea,CaLS was the optimal one in inhibiting acidification and increasing exchangeable acidity during incubation.Furthermore,the sharp reduction in the population sizes of ammonia-oxidizing bacteria(AOB)and ammonia-oxidizing archaea(AOA)confirmed the inhibition of nitrification via CaLS application.Therefore,compared to improving soil pHBC,CaLS may play a more important role in suppressing indirect acidification.Overall,γ-PGA-Ca was superior to PASP-Ca and CaLS in enhancing the soil pHBC and the its resistance to acidification induced by HNO_(3) addition,whereas CaLS was the best at suppressing urea-driven soil acidification by inhibiting nitrification.In conclusion,these results provide a reference for inhibiting soil re-acidification in intensive agricultural systems.

关键词： Calcium-based polymer Soil acidification pH buffering capacity Nitrification inhibition

A Provable Positivity-Preserving Local Discontinuous Galerkin Method for the Viscous and Resistive MHD Equations

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Communications on Applied Mathematics and Computation 2024年第1期6卷 279-310页

作者： Mengjiao Jiao yan Jiang Mengping zhang School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026AnhuiChina

In this paper,we construct a high-order discontinuous Galerkin(DG)method which can preserve the positivity of the density and the pressure for the viscous and resistive magnetohydrodynamics(VRMHD).To control the divergence error in the magnetic field,both the local divergence-free basis and the Godunov source term would be employed for the multi-dimensional VRMHD.Rigorous theoretical analyses are presented for one-dimensional and multi-dimensional DG schemes,respectively,showing that the scheme can maintain the positivity-preserving(PP)property under some CFL conditions when combined with the strong-stability-preserving time discretization.Then,general frameworks are established to construct the PP limiter for arbitrary order of accuracy DG schemes.Numerical tests demonstrate the effectiveness of the proposed schemes.

关键词： Viscous and resistive MHD equations Positivity-preserving Discontinuous Galerkin(DG)method High order accuracy

Glacial-interglacial cycles recorded in clay minerals from the eastern Tibetan Plateau over the last 800 ka and their indications

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Science China Earth Sciences 2024年第7期67卷 2162-2177页

作者： Xiaoyan zhang Chunxia zhang yan ZHAO Bin HU Zhengtang GUO Key Laboratory of Cenozoic geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Clay mineral proxies have been widely used to reconstruct changes in provenance and the paleoclimate.However,high-altitude clay mineral indications and long-term and orbital variations have not been fully explored.Herein,we present an800-ka clay-mineral record from a lacustrine sediment core(ZB13-C2)from the Zoige Basin on the eastern Tibetan Plateau(TP).X-ray diffraction and scanning electron microscopy were used to identify the clay mineral assemblages and their micromorphological characteristics of core ZB13-C2.The results revealed that the clay minerals in core ZB13-C2 are mainly illite,with small amounts of chlorite,kaolinite,and smectite(including irregular mixed-layers of illite-smectite(I/S)and chloritesmectite(C/S)).The clay mineral assemblages and proxies exhibit three stages of change,which are mainly controlled by the Zoige watershed range under different climate conditions.The watershed was limited to the southeastern region with altitudes ranging from~3500 to~4200 meters above sea level(m a.s.l.),and glacial-interglacial hydraulic erosion controlled the input of bedrock debris during 800-621 ka BP.It expanded to higher altitudes(~4200 to~4700 m a.s.l.)due to stronger seasonal freezethaw weathering without significant glacial-interglacial variations under a cooling and drying climate during 621-100 ka BP.Finally,it expanded to its highest altitudes of~4700 to~5200 m a.***.l.northwest of the watershed after 100 ka BP,and hydraulic erosion increased obviously under a warm climate of the interstadial MIS 3 on the TP.The watershed underwent two major expansions under different climatic conditions at~621 ka and 100 ka BP,with the wet/dry alternation became strong at~621 ka BP.These results reveal that long-term temperature changes and the wet/dry alternation at high altitudes controlled the watershed range and degree of the physical erosion,and that the indications of clay minerals should be carefully clarified before they are used as climate indicators,especially on the TP.

关键词： Quaternary Zoige Basin Lacustrine sediments Paleoenvironment Weathering