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Physical Processes Responsible for the Interannual Variability of Sea Ice Concentration in Arctic in Boreal Autumn since 1979

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Journal of Meteorological Research 2017年第3期31卷 468-475页

作者： Lei ZHANG Tim LI Climate Dynamics Research center and Earth System Modeling center International Laboratory on Climate and Environment ChangeNanjing University of Information Science & Technology Department of Atmospheric Sciences University of Hawaii

Arctic sea ice concentration （ASIC） in boreal autumn exhibits prominent interannual variability since 1979. The physical mechanism responsible for the year-to-year variation of ASIC is investigated through observational data analyses and idealized numerical modeling. It is found that the ASIC interannual variability is closely associated with the anomalous meridional circulations over the Northern Hemisphere, which is further linked with the tropical sea surface temperature （SST） forcing. A tropics-wide SST cooling anomaly leads to an enhanced meridional SST gradi- ent to the north of the equator in boreal summer, generating strengthened and northward shifting Hadley circulation over the Northern Hemisphere. Consequently, the meridional circulations are enhanced and pushed poleward, lead- ing to an enhanced descending motion at the North pole, surrounded by an ascending motion anomaly; the surface outflow turns into easterly anomalies, opposing the mean-state winds. As a result, positive cloudiness and weakened surface wind speed emerge, which reduce ASIC through changes in the surface latent heat flux and the downward longwave radiation.

关键词： Arctic sea ice variability interannual variability tropical forcing meridional circulations

Mechanism of Downcutting Erosion of Debris Flow over a Movable Bed

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Journal of Mountain Science 2015年第1期12卷 243-250页

作者： pan Hua-li Huang Jiang-cheng Ou Guo-qiang Key Laboratory of Mountain Hazards and Earth Surface Process Institute of Mountain Hazards and Environment CAS Asian International Rivers center Yunnan University

The phenomenon of debris flow is intermediate between mass movement and solid transport. Flows can be sudden, severe and destructive. Understanding debris flow erosion processes is the key to providing geomorphic explanations, but progress has been limited because the physical-mechanical properties, movement laws and erosion characteristics are different from those of sediment-laden flow. Using infinite slope theory, this research examines the process and mechanism of downcutting erosion over a moveable bed in a viscous debris flow gully. It focuses specifically on the scour depth and the critical slope for viscous debris flow,and formulas for both calculations are *** scour depth and the critical conditions of downcutting erosion are related to debris flow properties(sand volume concentration and flow depth) and gully properties(longitudinal slope,viscous and internal friction angle of gully materials,and coefficient of kinetic friction). In addition, a series of flume experiments was carried out to characterize the scouring process of debris flows with different properties. The calculated values agreed well with the experimental data. These theoretical formulas are reasonable, and using infinite slope theory to analyze down cutting erosion from viscous debris flow is feasible.

关键词： Debris flow Down cutting erosion Infinite slope theory Critical conditions Flumeexperiments

Progress and Prospects of Salt Lake Research in China

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Acta Geologica Sinica(English Edition) 2016年第4期90卷 1195-1235页

作者： ZHENG Mianping ZHANG Yongsheng LIU Xifang NIE Zhen KONG Fanjing QI Wen Jia Qingxian PU Linzhong HOU Xianhua WANG Hailei ZHANG Zhen KONG Weigang LIN Yongjie R&D center for Saline Lake and Epithermal Deposit CAGS Key Laboratory of Saline Lake Resources and environment Ministry of Land and Resources

China has unique salt lake resources, and they are distributed in the east of Eurasian salt lake subzone of the Northern Hemisphere Salt Lake Zone, mainly concentrated in the regions with modern mean annual precipitation lower than 500 mm. This paper preliminarily reviews the progress made in salt lake research in China for the past 60 years. In the research of Paleoclimate and paleoenvironment from salt lake sediments, a series of salts have been proposed to be indicators of paleoclimate, and have been well accepted by scholars. The chloride-sulfate depositional regions of the west Qaidam and the east Tarim have been revealed to be the drought center of China since the Quaternary, and more than 6 spreading stages of arid climate （salt forming） have been identified. Five pan-lake periods with highstands have been proved to exist during the late Quaternary on the Tibetan Plateau. In mineral resource prospecting and theories of the forming of salt deposits： the atlas （1：2500000） of hydrochemical zoning of salt lakes on the Tibetan Plateau has been compiled for the first time, revealing the zonal distribution and transition from carbonate type to chloride type from south to north and presenting corresponding mineral assemblages for different type of salt lakes; several large continental salt deposits have been discovered and the theory of continental potash deposition has been developed, including the salt deposition in deep basins surrounded by high mountains, the mineral deposition from multistage evolution through chains of moderate or shallow lakes with multilevels, the origin of potassium rich brines in gravel layers, and the forming of potassium deposits through the inheriting from ancient salt deposits, thus establishing the framework of ＂Continental Potash Deposition Theory＂; several new types of Mg-borate deposits have been discovered, including the ulexite and pinnoite bed in Da Qaidam Lake, Qinghai, the pinnoite and kurnakovite bed in Chagcam Caka, Tibet, th

关键词： progress in salt lake research in China salt lake deposits and paleoclimate salt deposition mineralization and salting theory of saline lakes utilization and exploitation salt lake agriculture

Facilities for Centralized Isolation and Quarantine for the Observation and Treatment of Patients with COVID-19

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Engineering 2021年第7期7卷 908-913页

作者： Xianliang Wang Jiao Wang Jin Shen John SJi Lijun pan Hang Liu Kangfeng Zhao Li Li Bo Ying Lin Fan Liubo Zhang Lin Wang Xiaoming Shi China CDC Key Laboratory of environment and Population Health National Institute of Environmental HealthChinese Center for Disease Control and PreventionBeijing 100021China environmental Research center Duke Kunshan UniversityKunshan 215316China Nicholas School of the environment Duke UniversityDurhamNC 27708USA center for Global Health School of Public HealthNanjing Medical UniversityNanjing 211166China

The coronavirus disease 2019(COVID-19)pandemic increased the burden on many healthcare systems and in the process,exposed the need for medical resources and physical *** few studies discussed the efficient utilization of medical resources and physical space so ***,this study aimed to summarize experiences related to facilities used for centralized isolation for medical observation and treatment during the COVID-19 pandemic in China and to provide suggestions to further improve the management of confirmed cases,suspected cases,and close *** China,three types of facilities for centralized isolation(Fangcang shelter hospitals,refitted non-designated hospitals,and quarantine hotels)underwent retrofitting for the treatment and isolation of confirmed and suspected *** facilities mitigated the immediate high demand for ***,in order to minimize infection risks in these facilities,regulators and governmental agencies implemented new designs,management measures,and precautionary measures to minimize infection *** countries and regions could refer to China’s experience in optimally allocating social resources in response to the COVID-19 *** a conclusion,government should allocate social resources and construct centralized isolation and quarantine facilities for an emergency response,health authorities should issue regulations for centralized isolation facilities and pay strict attention to the daily management of these facilities,a multidisciplinary administration team is required to support the daily operation of a centralized isolation facility,in-depth studies and international collaboration on the centralized isolation policy are encouraged.

关键词： Centralized isolation Risk control Infectious patients Close contacts Coronavirus disease

Tuning d-spacing of graphene oxide nanofiltration membrane for effective dye/salt separation

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Rare Metals 2023年第2期42卷 418-429页

作者： Chao Xing Chang-Yu Liu Chao Lai Shan-Qing Zhang center for Clean environment and Energy School of Environment and ScienceGold Coast CampusGriffith UniversitySouthportQLD4222Australia School of Chemistry and Materials Science Jiangsu Normal UniversityXuzhou221116China School of Biotechnology and Health Sciences Wuyi UniversityJiangmen529020China

The interlayer spacing(i.e.,d-spacing)plays a crucial role in determining the selectivity and permeability of nanofiltration membranes.A high-throughput directional filtration can be achieved by designing and controlling the *** this study,the d-spacing of a graphene oxide(GO)membrane was tuned and fixed to the desired value(approximately 0.79 nm)using a solution of polyethyleneimine(PEI)and GO at a PEI/GO mass ratio of15:*** resultant PEI/GO was deposited on a polyacrylonitrile(pan)substrate to form a robust composite nanofiltration membrane(a PEI/GO@pan membrane).The as-prepared membrane exhibited an ultrahigh flux of117.8 L·m^(-2)·h^(-1),and the rejection values for Direct Red80(DR80)and Na_(2)SO_(4)reached 99.7%andpan membrane exhibited an excellent filtration performance,and had a longer lifespan and excellent reusability because of its reinforced *** work suggested that tuning the d-spacing with PEI would be an effective strategy to achieve the anticipated functions of nanofiltration membranes.

关键词： Separation Nanofiltration Graphene oxide Membrane d-spacing

Inhibition of thrombin by functionalized C_(60)nanoparticles revealed via in vitro assays and in silico studies

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Journal of environmental Sciences 2018年第1期30卷 285-295页

作者： Yanyan Liu Jianjie Fu Wenxiao pan Qiao Xue Xian Liu Aiqian Zhang State Key Laboratory of environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Resources and environment University of Chinese Academy of SciencesBeijing 100190China Institute of environment and Health Jianghan UniversityWuhan 430056China

The studies on the human toxicity of nanoparticles（NPs） are far behind the rapid development of engineered functionalized NPs. Fullerene has been widely used as drug carrier skeleton due to its reported low risk. However, different from other kinds of NPs, fullerene-based NPs（C_（60） NPs） have been found to have an anticoagulation effect, although the potential target is still unknown. In the study, both experimental and computational methods were adopted to gain mechanistic insight into the modulation of thrombin activity by nine kinds of C_（60） NPs with diverse surface chemistry properties. In vitro enzyme activity assays showed that all tested surface-modified C_（60） NPs exhibited thrombin inhibition ability. Kinetic studies coupled with competitive testing using 3 known inhibitors indicated that six of the C_（60） NPs, of greater hydrophobicity and hydrogen bond（HB） donor acidity or acceptor basicity, acted as competitive inhibitors of thrombin by directly interacting with the active site of thrombin. A simple quantitative nanostructure-activity relationship model relating the surface substituent properties to the inhibition potential was then established for the six competitive *** docking analysis revealed that the intermolecular HB interactions were important for the specific binding of C_（60） NPs to the active site canyon, while the additional stability provided by the surface groups through van der Waals interaction also play a key role in the thrombin binding affinity of the NPs. Our results suggest that thrombin is a possible target of the surface-functionalized C_（60） NPs relevant to their anticoagulation effect.

关键词： Thrombin C_(60) nanoparticle(NP) Surface modification Activity inhibition Quantitative nanostructure-activity relationship Molecular docking

Theoretical study on the formation mechanism of polychlorinated dibenzothiophenes/thianthrenes from 2-chlorothiophenol molecules

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Journal of environmental Sciences 2018年第4期30卷 318-327页

作者： Xiaoqing Yu Jiamin Chang Xian Liu Wenxiao pan Aiqian Zhang State Key Laboratory of environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences College of Resources and environment University of Chinese Academy of Sciences

Homogeneous formation of polychlorinated dibenzothiophenes/thianthrenes（PCDT/TAs）,sulfurated compounds analogous to polychlorinated dibenzo-p-dioxin/dibenzofurans（PCDD/Fs）, has been well-documented to occur via radical–radical coupling reactions from chlorinated thiophenol precursors. However, the current understanding of the formation mechanism of PCDT/TAs is exclusively limited to the inherent point of view that chlorothiophenoxy radicals act as the only required intermediates for PCDT/TAs. This study investigates reaction pathways for the formation of PCDT/TAs involving two new types of radical species, i.e., substituted phenyl radicals and substituted thiophenoxyl diradicals. Taking 2-chlorothiophenol（2-CTP） as a model compound for chlorothiophenols,we found that apart from the mostly discussed chlorothiophenoxy radicals, substituted phenyl radicals and substituted thiophenoxyl diradicals could also be readily formed via the reaction of 2-CTP with H radicals. Furthermore, direct self-and cross-coupling of these radicals can result in the formation of PCDT/TAs, including 1-monochlorothianthrene（1-MCTA）, 1,6-dichlorothianthrene（1,6-DCTA）, 4,6-dichlorodibenzothiophene（4,6-DCDT）and 1,6-dichlorodibenzothiophene（1,6-DCDT）. The pathways proposed in this work are proven to be both thermodynamically and kinetically favorable. Particularly, comparisons were made between the formation mechanisms of sulfurated and oxygenated dioxin systems from an energetic point view, showing that replacing oxygen with sulfur atoms greatly reduces the activation barriers of the rate-controlling steps involved in the PCDT/TA formation processes compared with those involved for PCDD/Fs. The calculated results in this work may improve our understanding of the formation mechanism of PCDT/TAs from chlorothiophenol precursors and should be informative to environmental scientists.

关键词： Polychlorinated dibenzothiophenes/thianthrenes Formation mechanism Phenyl radicals Thiophenoxyl diradicals Density functional theory study

Mg^(2+) improves biomass production from soybean wastewater using purple non-sulfur bacteria

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Journal of environmental Sciences 2015年第2期27卷 43-46页

作者： pan Wu Guangming Zhang Jianzheng Li State Key Laboratory of Urban Water Resource and environment Harbin Institute of Technology School of environment & Resource Renmin University of China

Soybean wastewater was used to generate biomass resource by use of purple non-sulfur bacteria（PNSB）. This study investigated the enhancement of PNSB cell accumulation in wastewater by Mg2＋under the light-anaerobic condition. Results showed that with the optimal Mg2＋dosage of 10 mg/L, biomass production was improved by 70% to 3630 mg/L,and biomass yield also was improved by 60%. Chemical Oxygen Demand（COD） removal reached above 86% and hydraulic retention time was shortened from 96 to 72 hr. The mechanism analysis indicated that Mg2＋could promote the content of bacteriochlorophyll in photosynthesis because Mg2＋is the bacteriochlorophyll active center, and thus improved adenosine triphosphate（ATP） production. An increase of ATP production enhanced the conversion of organic matter in wastewater into PNSB cell materials（biomass yield） and COD removal, leading to more biomass production. With 10 mg/L Mg2＋, bacteriochlorophyll content and ATP production were improved by 60% and 33% respectively.

关键词： Purple non-sulfur bacteria Mg2+ Biomass resource Soybean wastewater Photosynthesis

MOF-derived Co-MOF,O-doped carbon as trifunctional electrocatalysts to enable highly efficient Zn-air batteries and water-splitting

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Journal of Energy Chemistry 2021年第5期30卷 290-298页

作者： Xinde Duan Na pan Can Sun Kexin Zhang Xukun Zhu Mingdao Zhang Li Song Hegen Zheng School of environmental Science and Engineering Nanjing University of Information Science&TechnologyJiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution ControlCollaborative Innovation Center of Atmospheric Environment and Equipment TechnologyNanjing 210044JiangsuChina State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210023JiangsuChina

Development of high-efficiency non-noble electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)is urgently needed for high-performance Zn-air batteries and overall water ***,a facile strategy to synthesize novel Co-MOF,O-doped carbon(Co-MOF-T)based on Zn,Co-doped glucosamine and ZIF-8 by pyrolysis at temperature T was *** prepared Co-MOF-800 showed a superior oxygen reduction reaction(ORR)activity comparable to that of commercial Pt/C *** addition,this catalyst shows great potential in the overall water splitting due to the excellent oxygen evolution reaction(OER)and hydrogen evolution reaction(HER)*** on the trifunctional activity,the primary Zn-air batteries using a Co-MOF-800 air electrode achieved a high open-circuit voltage of 1.38 V,a specific capacity of 671.6 mAh g^(-1) Zn,and a prominent peak power density of 144 mW cm^(-2).Also,the rechargeable Zn-air batteries based on CoMOF-800 air electrode could be smoothly run for 510 cycles with a low voltage gap of 0.58 ***,the trifunctional Co-MOF-800 catalyst was applied to boost the electrochemical water splitting,demonstrating its promising potential as a green energy material for practical applications.

关键词： Metal-organic frameworks Carbon catalysts Trifunctional electrocatalyst Metal-air batteries Water splitting