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| 1 | Seismically Induced Slope Instabilities and the Corresponding Treatments:the Case of a Road in the Wenchuan Earthquake Hit Region显示文摘On May 12, 2008, a magnitude 8.0 earthquake hit Wenchuan County, Sichuan Province resulted in great loss of life and properties.Besides, abundant landslides and slope failures were triggered in the most seriously hit areas and caused disastrous damages to infrastructures and public facilities.Moreover, abundant unstable slopes caused by the quake have the potential to cause damages for a considerable long period of time.The variety of these slopes and the corresponding treatments are connected with the topographical and geological conditions of the sites.It is decided to document and identify some of these major slope instabilities caused by the earthquake and their treatments.The paper shows the condition of a road in Dujiangyan through in situ explorations.The case history showed significant implications to the reconstruction of the quake-hit regions and future disaster prevention and management works. | LI Xinpo HE Siming | 2009 | Journal of Mountain Science2009，6，1： | 22 |
| 2 | A Possible Configuration with Motor-generator Pair for Renewable Energy Integration显示文摘High penetration rates of renewable energy will bring stability problems for the future power grid.One of the critical issues is lack of inertia.In this paper,a synchronous motor-generator pair(MGP)system is proposed as a possible solution for renewable energy integration to enhance inertia and improve grid stability.First,feasibility studies of MGP on inertia,damping,efficiency,and cost are presented.Second,an analytical model is established based on its rotor angle relation.An active power control scheme based on voltage phase difference between renewable energy source and grid is then proposed,and state equations of MGP are derived for small signal stability.Next,two experiments are designed and implemented to verify stable operation and active power regulation of the MGP system.A single-machine infinite bus system is tested to investigate small signal stability and frequency response of MGP.The results show that the MGP system has a solid base in physics and is a feasible solution for providing enough inertia and improving small signal performance in the power grid with high penetration of renewable energy.The paper concludes with a discussion on future research directions to gain a better understanding of MGP. | Siming Wei Yingkun Zhou Song Li Yongzhang Huang | 2017 | CSEE Journal of Power and Energy Systems2017，3，1： | 20 |
| 3 | Prevention and treatment technologies of railway tunnel water inrush and mud gushing in China显示文摘Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing. | Yong Zhao Pengfei Li Siming Tian | 2013 | Journal of Rock Mechanics and Geotechnical Engineering2013，5，6： | 16 |
| 4 | Single-cell transcriptome analysis of the novel coronavirus (SARS-CoV-2) associated gene ACE2 expression in normal and non-obstructive azoospermia (NOA) human male testes显示文摘Being infected by SARS-CoV-2 may cause damage to multiple organs in patients, such as the lung, liver and heart. Angiotensin-converting enzyme 2(ACE2), reported as a SARS-CoV-2 receptor, is also expressed in human male testes. This suggests a potential risk in human male reproductive system. However, the characteristics of ACE2-positive cells and the expression of other SARS-CoV-2 process-related genes are still worthy of further investigation. Here, we performed singlecell RNA seq(scRNA-seq) analysis on 853 male embryo primordial germ cells(PGCs) and 2,854 normal testis cells to assess the effects of the SARS-CoV-2 virus on the male reproductive system from embryonic stage to adulthood. We also collected and constructed the scRNA-seq library on 228 Sertoli cells from three non-obstructive azoospermia(NOA) patients to assess the effects at disease state. We found that ACE2 expressing cells existed in almost all testis cell types and Sertoli cells had highest expression level and positive cells ratio. Moreover, ACE2 was also expressed in human male PGCs. In adulthood, the level of ACE2 expression decreased with the increase of age. We also found that ACE2 positive cells had high expressions of stress response and immune activation-related genes. Interestingly, some potential SARS-CoV-2 process-related genes such as TMPRSS2, BSG, CTSL and CTSB had different expression patterns in the same cell type. Furthermore, ACE2 expression level in NOA donors’ Sertoli cells was significantly decreased. Our work would help to assess the risk of SARS-CoV-2 infection in the male reproductive system. | Xixi Liu Yidong Chen Wenhao Tang Li Zhang Wei Chen Zhiqiang Yan Peng Yuan Ming Yang Siming Kong Liying Yan Jie Qiao | 2020 | Science China(Life Sciences)2020，63，7： | 14 |
| 5 | Discrete Element Modeling of Debris Avalanche Impact on Retaining Walls显示文摘In China,gravity retaining walls are widely used as protection structures against rockfalls,debris flows and debris avalanches along the roads in mountainous areas.In this paper,the Discrete Element Method(DEM) has been used to investigate the impact of granular avalanches and debris flows on retaining walls.The debris is modeled as two dimensional circular disks that interact through frictional sliding contacts.The basic equations that control the deformation and motion of the particles are introduced.A series of numerical experiments were conducted on an idealized debris slide impacting a retaining wall.The parametric study has been performed to examine the influences of slope geometry,travel distance of the sliding mass,wall position,and surface friction on the impact force exerted on the wall.Results show that:1) the force achieves its maximum value when slope angle is equal to 60°,as it varies from 30° to 75°;2) an approximate linear relationship between the impact force and the storage area length is determined. | LI Xinpo HE Siming LUO Yu WU Yong | 2010 | Journal of Mountain Science2010，7，3： | 12 |
| 6 | Metaverse:Perspectives from graphics,interactions and visualization显示文摘The metaverse is a visual world that blends the physical world and digital world.At present,the development of the metaverse is still in the early stage,and there lacks a framework for the visual construction and exploration of the metaverse.In this paper,we propose a framework that summarizes how graphics,interaction,and visualization techniques support the visual construction of the metaverse and user-centric exploration.We introduce three kinds of visual elements that compose the metaverse and the two graphical construction methods in a pipeline.We propose a taxonomy of interaction technologies based on interaction tasks,user actions,feedback and various sensory channels,and a taxonomy of visualization techniques that assist user awareness.Current potential applications and future opportunities are discussed in the context of visual construction and exploration of the metaverse.We hope this paper can provide a stepping stone for further research in the area of graphics,interaction and visualization in the metaverse. | Yuheng Zhao Jinjing Jiang Yi Chen Richen Liu Yalong Yang Xiangyang Xue Siming Chen | 2022 | Visual Informatics2022，6，1： | 10 |
| 7 | Notoginsenoside Ft1 acts as a TGR5 agonist but FXR antagonist to alleviate high fat diet-induced obesity and insulin resistance in mice显示文摘Obesity and its associated complications are highly related to a current public health crisis around the world.A growing body of evidence has indicated that G-protein coupled bile acid(BA) receptor TGR5(also known as Gpbar-1) is a potential drug target to treat obesity and associated metabolic disorders.We have identified notoginsenoside Ftl(Ftl) from Panax notoginseng as an agonist of TGR5 in vitro.However,the pharmacological effects of Ftl on diet-induced obese(DIO) mice and the underlying mechanisms are still elusive.Here we show that Ftl(100 mg/100 diet) increased adipose lipolysis,promoted fat browning in inguinal adipose tissue and induced glucagon-like peptide-1(GLP-1) secretion in the ileum of wild type but not Tgr5^(-/-) obese mice.In addition,Ftl elevated serum free and taurineconjugated bile acids(BAs) by antagonizing Fxr transcriptional activities in the ileum to activate Tgr5 in the adipose tissues.The metabolic benefits of Ftl were abolished in Cyp27 al^(-/-) mice which have much lower BA levels.These results identify Ftl as a single compound with opposite activities on two key BA receptors to alleviate high fat diet-induced obesity and insulin resistance in mice. | Lili Ding Qiaoling Yang Eryun Zhang Yangmeng Wang Siming Sun Yingbo Yang Tong Tian Zhengcai Ju Linshan Jiang Xunjiang Wang Zhengtao Wang Wendong Huang Li Yang | 2021 | Acta Pharmaceutica Sinica B2021，11，6： | 10 |
| 8 | Low-noise 1.3 μm InAs/GaAs quantum dot laser monolithically grown on silicon显示文摘We report low-noise, high-performance single transverse mode 1.3 μm InAs/GaAs quantum dot lasers monolithically grown on silicon(Si) using molecular beam epitaxy. The fabricated narrow-ridge-waveguide Fabry–Perot(FP) lasers have achieved a room-temperature continuous-wave(CW) threshold current of 12.5 mA and high CW temperature tolerance up to 90°C. An ultra-low relative intensity noise of less than-150 dB∕Hz is measured in the 4–16 GHz range. Using this low-noise Si-based laser, we then demonstrate 25.6 Gb/s data transmission over13.5 km SMF-28. These low-cost FP laser devices are promising candidates to provide cost-effective solutions for use in uncooled Si photonics transmitters in inter/hyper data centers and metropolitan data links. | MENGYA LIAO SIMING CHEN ZHIXIN LIU YI WANG LALITHA PONNAMPALAM ZICHUAN ZHOU JIANG WU MINGCHU TANG SAMUEL SHUTTS ZIZHUO LIU PETER M.SMOWTON SIYUAN YU ALWYN SEEDS HUIYUN LIU | 2018 | Photonics Research2018，，11： | 7 |
| 9 | Study on the Rainfall and Aftershock Threshold for Debris Flow of Post-earthquake显示文摘Due to the special condition of provenance and disaster environment after '5·12' Earthquake, the probability and conditions of the occurrence of gully debris flow change greatly after the event, which make it difficult to prevent disaster effectively. In this study the hydrological model of ground water table in loose sediment is established. According to infinite slope theory, the safety factor of deposits is defined as the ratio of resistance force to driving force. The starting condition of post-earthquake gully debris flow is clearly studied by analyzing the effects of rainfall intensity, seismic strength, slope gradient and mechanical properties on the balance of accumulation body. Then the formulas of rainfall and aftershock threshold for starting of gully debris flow are proposed, and an example is given to illustrate the effect of rainfall, aftershocks and their coupling action on a debris flow. The result shows the critical rainfall intensity decreases as the lateral seismic acceleration and channel gradient increases, while the critical intensity linearly increases as the friction angle increases. | HE Siming LI Dexin WU Yong LUO Yu | 2011 | Journal of Mountain Science2011，8，5： | 7 |
| 10 | GIS-based Earthquake-Triggered Landslide Hazard Zoning Using Contributing Weight Model显示文摘Earthquake-triggered landslides have aroused widespread attention because of their tremendous ability to harm people's lives and properties.The best way to avoid and mitigate their damage is to develop landslide hazard maps and make them available to the public in advance of an earthquake.Future construction can then be built according to the level of hazard and existing structures can be retrofit as necessary.During recent years various approaches have been made to develop landslide hazard maps using statistical analysis or physical models.However,these methods have limitations.This study introduces a new GIS-based approach,using the contributing weight model,to evaluate the hazard of seismically-induced landslides.In this study,the city and surrounding area of Dujiangyan was selected as the research area because of its moderate-high seismic activity.The parameters incorporated into the model that related to the probability of landslide occurrence were:slope gradient,slope aspect,geomorphology,lithology,base level,surface roughness,earthquake intensity,fault proximity,drainage proximity,and road proximity.The parameters were converted into raster data format with a resolution of 25×25m2 pixels.Analysis of the GIS correlations shows that the highest earthquake-induced landslide hazard areas are mainly in the hills and in some of the moderately steep mountainous areas of central Dujiangyan.The highest hazard zone covers an area of 11.1% of the study area,and the density distribution of seismically-induced landslides was 3.025/km2 from the 2008 Wenchuan earthquake.The moderately hazardous areas are mainly distributed within the moderately steep mountainous regions of the northern and southeastern parts of the study area and the hills of the northeastern part;covering 32.0% of the study area and with a density distribution of 2.123/km2 resulting from the Wenchuan earthquake.The lowest hazard areas are mainly distributed in the topographically flat plain in the northeastern part and some of the relatively gently slopes in the moderately steep mountainous areas of the northern part of Dujiangyan and the surrounding area.The lowest hazard areas cover 56.9% of the study area and exhibited landslide densities of 0.941/km2 and less from the Wenchuan earthquake.The quality of the hazard map was validated using a comparison with the distribution of landslides that were cataloged as occurring from the Wenchuan earthquake.43.1% of the study area consists of high and moderate hazardous zones,and these regions include 83.5% of landslides caused by the Wenchuan earthquake.The successful analysis shows that the contributing weight model can be effective for earthquake-triggered landslide hazard appraisal.The model's results can provide the basis for risk management and regional planning is. | WANG Meng | 2010 | Journal of Mountain Science2010，7，4： | 6 |
| 11 | Artemisinin mimics calorie restriction to extend yeast lifespan via a dual-phase mode: a conclusion drawn from global transcriptome profiling显示文摘Calorie restriction(CR) promotes longevity among distinct organisms from yeast to mammals. Although CR-prolonged lifespan is believed to associate with enhanced respiratory activity, it is apparently controversial for accelerated energy consumption regardless of insufficient nutrient intake. In reconciling the contradiction of less food supply versus much metabolite dispense, we revealed a CR-based mode of dual-phase responses that encompass a phase of mitochondrial enhancement(ME) and a phase of post-mitochondrial enhancement(PME), which can be distinguished by the expression patterns and activity dynamics of mitochondrial signatures. ME is characterized by global antioxidative activation, and PME is denoted by systemic metabolic modulation. CR-mediated aging-delaying effects are replicated by artesunate, a semi-synthetic derivative of the antimalarial artemisinin that can alkylate heme-containing proteins, suggesting artesunate-heme conjugation functionally resembles nitric oxide-heme interaction. A correlation of artesunate-heme conjugation with cytochrome c oxidase activation has been established from adduct formation and activity alteration. Exogenous hydrogen peroxide also mimics CR to trigger antioxidant responses, affect signaling cascades, and alter respiratory rhythms, implying hydrogen peroxide is engaged in lifespan extension. Conclusively, artesunate mimics CR-triggered nitric oxide and hydrogen peroxide to induce antioxidative networks for scavenging reactive oxygen species and mitigating oxidative stress, thereby directing metabolic conversion from anabolism to catabolism, maintaining essential metabolic functionality, and extending life expectancy in yeast. | WANG DaTing WU Ming LI SiMing GAO Qian ZENG QingPing | 2015 | Science China(Life Sciences)2015，58，5： | 6 |
| 12 | D-二聚体预测稳定型冠状动脉性心脏病患者的长期病因特异性死亡率、心血管事件和癌症显示文摘交联纤维蛋白的降解产物D-二聚体是高凝状态和血栓形成事件的标志。D-二聚体水平中度升高与血管疾病患者静脉和动脉事件的风险相关。在缺血性疾病长期普伐他汀干预(long-term intervention with pravastatin in ischemic disease,LIPID)试验中,研究者在存在其他危险因素的背景下,评估了D-二聚体水平在预测长期血管转归、病因特异性死亡率和新发癌症中的作用。 | 刘青 叶鹏 Simes J Robledo KP White HD Espinoza D Stewart RA Sullivan DR Zeller T Hague W Nestel PJ Glasziou PP Keech AC Elliott J Blankenberg S Tonkin AM LIPID study investigators | 2018 | 中华高血压杂志2018，26，3： | 6 |
| 13 | Cellulose fibers-reinforced self-expanding porous composite with multiple hemostatic efficacy and shape adaptability for uncontrollable massive hemorrhage treatment显示文摘Uncontrollable hemorrhage leads to high mortality and thus effective bleeding control becomes increasingly important in the military field and civilian trauma arena.However,current hemostats not only present limitation when treating major bleeding,but also have various side effects.Here we report a self-expanding porous composites(CMCP)based on novel carboxymethyl cellulose(CMC)fibers and acetalized polyvinyl alcohol(PVA)for lethal hemorrhage control.The CMC fibers with uniform fibrous structure,high liquid absorption and procoagulant ability,are evenly interspersed inside the composite matrix.The obtained composites possess unique fiber-porous network,excellent absorption capacity,fast liquid-triggered self-expanding ability and robust fatigue resistance,and their physicochemical performance can be fine-tuned through varying the CMC content.In vitro tests show that the porous composite exhibits strong blood clotting ability,high adhesion to blood cells and protein,and the ability to activate platelet and the coagulation system.In vivo hemostatic evaluation further confirms that the CMCP presents high hemostatic efficacy and multiple hemostatic effects in swine femoral artery major hemorrhage model.Additionally,the CMCP will not fall off from the injury site,and is also easy to surgically remove from the wound cavity after the hemostasis.Importantly,results of CT tomography and 3D reconstruction indicate that CMCP can achieve shape adaptation to the surrounding tissues and the wound cavities with different depths and shapes,to accelerate hemostasis while protecting wound tissue and preventing infection. | Yansen Wang Yifan Zhao Longxue Qiao Faxing Zou Yajie Xie Yudong Zheng Yong Chao Ying Yang Wei He Siming Yang | 2021 | Bioactive Materials2021，6，7： | 6 |
| 14 | Xeno-repopulation of Fah^(-/-)Nod/Scid mice livers by human hepatocytes显示文摘Functional human hepatocytes xenografted into the liver of mice can be used as a model system to study pharmacokinetics,infection of hepatitis viruses,and the efficacy of hepatitis vaccines.Significant levels of liver xeno-repopulation have been reported in Fah-/-Rag2-/-Il2rg-/-mice.However,the high mortality and low breeding rate of this model may hinder its application.A new model,termed Fah-/-Nod/Scid mice,which combines the advantages of liver repopulation in Fah-/-mice with the ease of xenotransplantation in Nod/Scid mice was obtained by gradual cross-breeding.Fah-/-Nod/Scid mice were easily maintained in breeding colonies and in adult animal care facilities.FK506 treatment combined with gradual withdrawal of NTBC before cell transplantation ensured that Fah-/-Nod/Scid mice were susceptible to liver xeno-repopulation by human hepatocytes;the proportion of engrafted human hepatocytes reached 33.6%.The function of the expanded human hepatocytes within the chimeric liver was confirmed by weight curve analysis,the expression of characteristic proteins,and the biochemical analysis of liver function.These results show that Fah-/-Nod/Scid mice are an ideal humanized liver mouse model with many useful applications. | SU BaoLiang LIU ChangCheng XIANG Dao ZHANG HaiBin YUAN SiMing WANG MinJun CHEN Fei ZHU HaiYing HE ZhiYing WANG Xin HU YiPing | 2011 | Science China(Life Sciences)2011，54，3： | 5 |
| 15 | Coupled Model of Two-phase Debris Flow,Sediment Transport and Morphological Evolution显示文摘The volume fraction of the solid and liquid phase of debris flows,which evolves simultaneously across terrains,largely determines the dynamic property of debris flows. The entrainment process significantly influences the amplitude of the volume fraction. In this paper,we present a depth-averaged two-phase debris-flow model describing the simultaneous evolution of the phase velocity and depth,the solid and fluid volume fractions and the bed morphological evolution. The model employs the Mohr–Coulomb plasticity for the solid stress,and the fluid stress is modeled as a Newtonian viscous stress. The interfacial momentum transfer includes viscous drag and buoyancy. A new extended entrainment rate formula that satisfies the boundary momentum jump condition(Iverson and Ouyang,2015) is presented. In this formula,the basal traction stress is a function of the solid volume fraction and can take advantage of both the Coulomb and velocity-dependent friction models. A finite volume method using Roe's Riemann approximation is suggested to solve the equations. Three computational cases are conducted and compared with experiments or previous results. The results show that the current computational model and framework are robust and suitable for capturing the characteristics of debris flows. | HE Siming OUYANG Chaojun LIU Wei WANG Dongpo | 2016 | Acta Geologica Sinica(English Edition)2016，90，6： | 5 |
| 16 | Survival after neoadjuvant chemotherapy or chemoradiotherapy for resectable oesophageal carcinoma: an updated meta-analysis显示文摘 | Katrin M Sjoquist Bryan H Burmeister B Mark Smithers John R Zalcberg R John Simes Andrew Barbour Val Gebski | 2011 | Lancet Oncology2011，，7： | 4 |
| 17 | Developing conservation strategies for Pinus koraiensis and Eleutherococcus senticosus by using model-based geographic distributions显示文摘We described potential changes in the geographic distribution and occurrence probability of Pinus koraiensis Sieb. et Zucc. and Eleutherococcus senticosus(Rupr. et Maxim.) Maxim. in the counties of northeast China. This information was used to identify priority areas for protection and provide protection and management recommendations within each studied county. The two species were mapped in 2884 study plots throughout this region over a 4-year period(38 400N–53 300 N, 115 050E–135 020E). We used the species distribution models(Maxent), systematic conservation planning models(Marxan), and Geographic Information Systems(Arc GIS10.0). The distributions of two species were correlated in the study area, enabling unique and economically viable joint conservation measures to be implemented. Three models were combined to identify feasible priority conservation sites. We used local spatial statistics to assess all identified conservation areas in relation to potential climate change based shifts in the geographic distribution of the two species. Model-based conservation strategies were used to identify effective measures to protect and utilize these two tree species in the study region. This study presents a novel technique for assessing wild plant distributions, in addition to serving as a model for the conservation of other species within the framework of general forest management, ecological construction, and geographical surveying. | Jizhong Wan Chunjing Wang Jinghua Yu Siming Nie Shijie Han Juzhao Liu Yuangang Zu Qinggui Wang | 2016 | Journal of Forestry Research2016，27，2： | 4 |
| 18 | Deep plug-and-play priors for spectral snapshot compressive imaging显示文摘We propose a plug-and-play(Pn P) method that uses deep-learning-based denoisers as regularization priors for spectral snapshot compressive imaging(SCI). Our method is efficient in terms of reconstruction quality and speed trade-off, and flexible enough to be ready to use for different compressive coding mechanisms. We demonstrate the efficiency and flexibility in both simulations and five different spectral SCI systems and show that the proposed deep Pn P prior could achieve state-of-the-art results with a simple plug-in based on the optimization framework. This paves the way for capturing and recovering multi-or hyperspectral information in one snapshot,which might inspire intriguing applications in remote sensing, biomedical science, and material science. Our code is available at: http://gffzz188fe103f8f1460aswqxvfnfc6kp96xvw.ffgz.tsg.suse.edu.cn/zsm1211/Pn P-CASSI. | SIMING ZHENG YANG LIU ZIYI MENG MU QIAO ZHISHEN TONG XIAOYU YANG SHENSHENG HAN XIN YUAN | 2021 | Photonics Research2021，9，2： | 4 |
| 19 | Northern Hemisphere Sudden Stratospheric Warming and Its Downward Impact in Four Chinese CMIP6 Models显示文摘Using the World Meteorological Organization definition and a threshold-based classification technique,simulations of vortex displacement and split sudden stratospheric warmings(SSWs)are evaluated for four Chinese models(BCC-CSM2-MR,FGOALS-f3-L,FGOALS-g3,and NESM3)from phase 6 of the Coupled Model Intercomparison Project(CMIP6)with the Japanese 55-year reanalysis(JRA-55)as a baseline.Compared with six or seven SSWs in a decade in JRA-55,three models underestimate the SSW frequency by~50%,while NESM3 doubles the SSW frequency.SSWs mainly appear in midwinter in JRA-55,but one-month climate drift is simulated in the models.The composite of splits is stronger than displacements in both the reanalysis and most models due to the longer pulse of positive eddy heat flux before onset of split SSWs.A wavenumber-1-like temperature anomaly pattern(cold Eurasia,warm North America)before onset of displacement SSWs is simulated,but cold anomalies are mainly confined to North America after displacement SSWs.Although the lower tropospheric temperature also displays a wavenumber-1-like pattern before split SSWs,most parts of Eurasia and North America are covered by cold anomalies after split SSWs in JRA-55.The models have different degrees of fidelity for the temperature anomaly pattern before split SSWs,but the wavenumber-2-like temperature anomaly pattern is well simulated after split SSWs.The center of the negative height anomalies in the Pacific sector before SSWs is sensitive to the SSW type in both JRA-55 and the models.A negative North Atlantic Oscillation is simulated after both types of SSWs in the models,although it is only observed for split SSWs. | Jian RAO Siming LIU Yuanhao CHEN | 2021 | Advances in Atmospheric Sciences2021，38，2： | 4 |
| 20 | Chemical characteristics,oxidative potential,and sources of PM_(2.5)in wintertime in Lahore and Peshawar,Pakistan显示文摘The chemical characteristics,oxidative potential,and sources of PM_(2.5)were analyzed at the urban sites of Lahore and Peshawar,Pakistan in February 2019.Carbonaceous species,water soluble ions,and metal elements were measured to investigate the chemical composition and sources of PM_(2.5).The dithiothreitol(DTT)consumption rate was measured to evaluate the oxidative potential of PM_(2.5).Both cities showed a high exposure risk of PM_(2.5)regarding its oxidative potential(DTT v).Carbonaceous and some of the elemental species of PM_(2.5)correlated well with DTT v in both Lahore and Peshawar.Besides,the DTT v of PM_(2.5)in Lahore showed significant positive correlation with most of the measured water soluble ions,however,ions were DTT-inactive in Peshawar.Due to the higher proportions of carbonaceous species and metal elements,Peshawar showed higher mass-normalized DTT activity of PM_(2.5)compared to Lahore although the average PM_(2.5)concentration in Peshawar was lower.The high concentrations of toxic metals also posed serious non-carcinogenic and carcinogenic risks to the residents of both cities.Principle component analysis coupled with multiple linear regression was applied to investigate different source contributions to PM_(2.5)and its oxidative potential.Mixed sources of traffic and road dust resuspension and coal combustion,direct vehicle emission,and biomass burning and formation of secondary aerosol were identified as the major sources of PM_(2.5)in both cities.The findings of this study provide important data for evaluation of the potential health risks of PM_(2.5)and for formulation of efficient control strategies in major cities of Pakistan. | Mushtaq Ahmad Qing Yu Jing Chen Siming Cheng Weihua Qin Yuepeng Zhang | 2021 | Journal of Environmental Sciences2021，33，4： | 4 |
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