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CO_2 seasonal variation and global change: Test global warming from another point of view

Research in Cold and Arid Regions 2017年第1期9卷 46-53页

作者： XiuMing Liu Jiasheng Chen School of Geographical Sciences Fujian Normal University Department of Environment and Geography Macquarie University

CO2 and temperature records at Mauna Loa, Hawaii, and other observation stations show that the correlation between CO2 and temperature is not significant. These stations are located away from big cities, and in various latitudes and hemi-spheres. But the correlation is significant in global mean data. Over the last five decades, CO2 has grown at an accelerating rate with no corresponding rise in temperature in the stations. This discrepancy indicates that CO2 probably is not the driving force of temperature change globally but only locally （mainly in big cities）. We suggest that the Earth＇s atmospheric concentration of CO2 is too low to drive global temperature change. Our empirical perception of the global warming record is due to the urban heat island effect： temperature rises in areas with rising population density and rising industrial activity. This effect mainly occurs in the areas with high population and intense human activities, and is not representative of global warming. Regions far from cities, such as the Mauna Loa highland, show no evident warming trend. The global monthly mean temperature calculated by record data, widely used by academic researchers, shows R2=0.765, a high degree of correlation with CO2 . However, the R2 shows much less significance （mean R2=0.024） if calculated by each record for 188 selected stations over the world. This test suggests that the inflated high correlation between CO2 and temperature （mean R2=0.765-0.024=0.741） used in reports from the Intergovernmental Panel on Climate Change （IPCC） was very likely produced during data correction and processing. This untrue global monthly mean temperature has created a picture： human emission drives global warming.

关键词： CO2 Mauna Loa Hawaii seasonal variations greenhouse effect global warming

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Recent advances and emerging trends in antiviral defense networking in rice

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The Crop Journal 2021年第3期9卷 553-563页

作者： Lu Wang Huiting Xie Xiaoyuan Zheng Jiasheng Chen Shuai Zhang Jianguo Wu Vector-borne Virus Research Center Fujian Province Key Laboratory of Plant VirologyState Key Laboratory of Ecological Pest Control for Fujian and Taiwan CropsFujian Agriculture and Forestry UniversityFuzhou 350002FujianChina

Plants and viruses coexist in the natural ecosystem for extended periods of time,interacting with each other and even coevolving,maintaining a dynamic balance between plant disease resistance and virus pathogenicity.During virus–host interactions,plants often exhibit abnormal growth and development.However,plants do not passively withstand virus attacks but have evolved sophisticated and effective defense mechanisms to resist,limit,or undermine virus infections.It is widely believed that the initial stage of infection features the most intense interactions between the virus and the host and the greatest variety of activated signal transduction pathways.This review describes the most recent findings in rice antiviral research and discusses a variety of rice antiviral molecular mechanisms,including those based on R genes and recessive resistance,RNA silencing,phytohormone signaling,autophagy and WUSmediated antiviral immunity.Finally,we discuss the challenges and future prospects of breeding rice for enhanced virus resistance.

关键词： Rice antivirus R gene RNA silencing Recessive resistance Hormone

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DEM investigation of macro-and micro-mechanical properties of rigid-grain and soft-chip mixtures

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Particuology 2021年第2期19卷 128-139页

作者： Junqi Zhang Xiaobin chen jiasheng Zhang Peerapong Jitsangiam Xiang Wang Central South University School of Civil EngineeringChangshaHunanChina Chiang Mai University Department of Civil EngineeringChiang MaiThailand

We investigated the macro-and micro-mechanical properties of rigid-grain and soft-chip mixtures(GCMs)through numerical simulations using the discrete element method.We present a novel framework for the discrete modeling of soft chips and rigid grains in conjunction with calibration processes.Several numerical triaxial tests were also performed on GCMs with 0%,10%,20%,and 30%volumetric chip contents,P.The simulation results demonstrate that increasing P leads to higher GCM toughness,higher deviatoric peak stress,and higher corresponding shear strain.Higher P also contributes to more volume contraction and less dilation.The friction angles at both the peak and residual state significantly increase with increasing P.In view of the micro-mechanical features,strong contact force chains develop along the loading direction,which results in considerable anisotropy in the peak and residual states.Both the formation of strong force chains and rotation of grains decrease with increasing P,whereas the grain sliding percentage increases.The tensile force is mobilized with shearing and higher P leads to less mobilization of the tensile force.These findings are useful for better understanding the internal structure of GCMs with different soft-chip contents,especially in granular mixture mechanics and geomechanics.

关键词： Rubber chips Rigid-soft mixtures Micro-mechanical properties Triaxial test Discrete element method

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Tracing the Methane Events by Stable Carbon Isotopes of Benthic Foraminifera at Glacial Periods in the Andaman Sea

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Journal of Earth Science 2022年第6期33卷 1571-1582页

作者： Yue Cen jiasheng Wang Xuan Ding Dorrik Stow Zhou Wang Can chen Xiaochen Ma Hubei Key Laboratory of Marine Geological Resources College of Marine Science and TechnologyState Key Laboratory of Biogeology and Environmental GeologyChina University of GeosciencesWuhan430074China School of the Marine Sciences China University of GeosciencesBeijing100083China Institute of Geo-Energy Engineering Heriot-Watt UniversityEdinburghEH 144ASUK State Key Laboratory of Marine Geology Tongji UniversityShanghai200092China

Stable isotopes of carbon and oxygen variations in foraminiferal shells have been widely used in paleo-environment studies.However,studies about the shells of benthic foraminifera in methanehydrate-bearing sediments as reliable geochemical proxies to reconstruct the potential methane release events in the geologic past are rare.In this study,we present the stable carbon and oxygen isotopes of fossil benthic foraminifera including one epifaunal species(Cibicidoides wuellerstorfi)and two infaunal species(Bulimina mexicana and Uvigerina peregrina)from the Site U1447 of IODP 353 Expedition to trace methane events in the Andaman Sea,where one of the thickest and deepest gas hydrate stability zones was discovered.Theδ^(13)C values of benthic foraminifera show that there are eight distinct intervals with negative values in the last~10 Myr,interpreted as a record of long-term fluctuations in methane emission.Six of these methane events occurred during the glacial sea-level lowstands in the last~1.1 Myr.We,therefore,infer that the trigger mechanism for these events might be the hydrate destabilization caused by sea level fall.The methane events that occurred at~2.11 and~5.93 Ma are more likely related to the sudden changes in sedimentation,either slide events or marked variations in sedimentation rate.

关键词： benthic foraminifera stable carbon and oxygen isotopes methane events gas hydrates IODP 353 Site U1447 Andaman Sea

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Sigmatropic rearrangements of B(MIDA)-propargylic alcohols towards the diverse synthesis of α-functionalized organoborons

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Science China Chemistry 2024年第2期67卷 568-575页

作者： jiasheng Qian Li-Cai Liu Zhi-Hao chen Yuan Liu Yin Li Qingjiang Li Honggen Wang Guangdong Key Laboratory of Chiral Molecule and Drug Discovery School of Pharmaceutical SciencesSun Yat-Sen UniversityGuangzhou510006China

α-Functionalized organoborons are useful building blocks and key structural elements in functional molecules.Their previous synthesis relied on the famous Matteson reaction or the late-stage borylative modification of alkynes or alkenes.Recently,the synthetic transformation of borylated building blocks offers another useful strategy and is currently actively explored.We report herein that B(MIDA)-propargylic alcohols(BPAs) are a useful type of borylated building blocks.Bearing two complementary functional group handles(alkyne and hydroxyl) in close proximity,the redox-neutral [3,3] and [2,3] sigmatropic rearrangements of BPAs allow the efficient synthesis of several types of α-functionalized boronates,including α,β-unsaturated acylborons,α-S/P-substituted allenylborons,boryl-substituted thiazoles and a borylated α,β-unsaturated hydrazine,some of which are otherwise challenging targets using other synthetic methods.

关键词： organoboron diverse synthesis sigmatropic rearrangement heteroarene amide

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Synthesis of allenyl-B(MIDA)via hydrazination/fragmentation reaction of B(MIDA)-propargylic alcohol

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Chinese Chemical Letters 2023年第1期34卷 333-336页

作者： jiasheng Qian Zhi-Hao chen Yuan Liu Yin Li Qingjiang Li Shi-Liang Huang Honggen Wang Guangdong Key Laboratory of Chiral Molecule and Drug Discovery School of Pharmaceutical SciencesSun Yat-Sen UniversityGuangzhou 510006China

Allenylboronates represent a very intriguing class of organoborons but are challenging to synthesis.In addition,these compounds are typically unstable,rendering the separation difficult.We report herein a practical and concise route to a new class of stable,easy-separable allenyl B(MIDA)via a hydrazination/fragmentation of B(MIDA)-propargylic alcohols.The synthesis of optically active allenyl B(MIDA)was also achieved.Interesting reactivity of the resulting product was observed.

关键词： Allenyl boronate Mitsunobu reaction Mida boronates Hydrazination Fragmentation Chirality transfer

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Effect of aging treatment on microstructure and corrosion behavior of a Fe-18Cr-15Mn-0.66N stainless steel

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Journal of Materials Science & Technology 2022年第12期107卷 197-206页

作者： Yanxin Qiao Xinyi Wang Lanlan Yang Xiaojing Wang Jian chen Zhengbin Wang Huiling Zhou jiasheng Zou Fuhui Wang School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China

The effect of aging treatment on the microstructure and corrosion behavior of a Fe-18Cr-15Mn-0.66N high-nitrogen stainless steel(HNSS) in 3.5 wt.% Na Cl solution was investigated using a series of electrochemical tests, scanning electronic microscopy(SEM), X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The results showed that the aging treatment led to the precipitation of CrN particles along the grain boundaries and their morphologies changed from dispersive particles to continuous network as the aging time increased up to 60 min. Aging time had minor effects on the corrosion potential and corrosion current density, but resulted in the sharp decrease in the pitting corrosion potential.The passive film behaved as a n-type semiconductor, and the donor density of the passive film increased with the aging time. Meanwhile, the fraction of stable oxide(CrO) in the passive film decreased with the aging time. It demonstrates that the aging treatment deteriorated the protectiveness of the passive film, hence weakened the corrosion resistance of HNSS.

关键词： High-nitrogen stainless steel Corrosion Aging treatment Passive film

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Carbon Isotope Gradient of the Ediacaran Cap Carbonate in the Shennongjia Area and Its Implications for Ocean Stratification and Palaeogeography

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Journal of Earth Science 2017年第2期28卷 187-195页

作者： Guangzhe Wang jiasheng Wang Zhou Wang Can chen Junxia Yang State Key laboratory of Biogeology and Environment Geology School of Earth Sciences China University of Geosciences Institute of Karst Geology CAGS Key Laboratory of Karst Ecosystem and Treatment of Rocky Desertification MLR

The geochemistry and paleogeography of the Doushantuo succession in the Shennongjia area have been insufficiently studied. Here, we report on the carbon and oxygen isotope compositions of Ediacaran Doushantuo cap carbonates from four sections（Longxi, Muyu, Yazikou and Songluo） in the Shennongjia area. A large C-isotopic gradient（~5‰） between the Longxi and Songluo sections, here identified for the first time, is inferred to have been dynamically maintained by photosynthesis in surface waters and anaerobic oxidation of dissolved organic carbon（DOC） in deep waters. Spatial variation in C-isotope chemostratigraphy among the four sections was related to Marinoan post-glacial sea-level elevation changes. At Longxi, a positive δ^（13）C_（carb） shift below the horizon containing tepee-like structure resulted from intense photosynthesis during early regression. A negative δ^（13）C_（carb） shift within the tepee-horizon was triggered by sulfate reduction and freshwater mixing with ^（13）C-depleted dissolved inorganic carbon（DIC） during late regression. A positive δ^（13）C_（carb） excursion in the uppermost part of the cap carbonate was related to enhance primary productivity and organic matter burial during early transgression. At Muyu, the carbon isotopic variation tendency, which is similar to that at Longxi, may have been mildly influenced by the surface water environment. At Songluo, the positive δ^（13）C_（carb） excursion, up to-4‰ in the lower part of the cap carbonate, was probably associated with methanogenesis in deep waters during late transgression to early regression and subsequently disappeared due to decomposition of methane hydrate during late regression. At Yazikou, the consistently stable δ^（13）C_（carb） values around-4‰ indicate that the cap carbonate may have deposited at intermediate water depths. As evidenced by diagnostic sedimentary characteristics of the study sections, the palaeogeographic framework of the Shennongjia area exhibited deepening from SE to NW during the Early Ediacaran Period in the aftermath

关键词： Ediacaran Doushantuo cap carbonate carbon isotope stratification palaeogeography,Shennongjia.

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Ynamide Protonation-Initiated Cis-Selective Polyene Cyclization and Reaction Mechanism

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CCS Chemistry 2022年第9期4卷 2991-3001页

作者： jiasheng Yao chen-Long Li Xing Fan Zhou Wang Zhi-Xiang Yu Junfeng Zhao School of Pharmaceutical Sciences Guangzhou Medical UniversityGuangzhou 511436 College of Chemistry and Chemical Engineering Jiangxi Normal UniversityNanchang 330022 College of Chemistry Peking UniversityBeijing 100871 School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an 710072 State Key Laboratory of Elemento-Organic Chemistry Nankai UniversityTianjin 300071

The diastereoselectivity of conventional polyene cyclization reactions is highly dependent on the configuration of the internal alkenes,where E-poly enes provide trans-decalins,while Z-polyenes offer cis-decalins.Although polyene cyclization has evolved into a reliable and widely used strategy for the construction of trans-decalin frameworks of terpene and steroid natural products,its application for cis-decalin framework is extremely challenging.

关键词： polyene cyclization cis-decalin framework ynamide protonation double protonation mechanism

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Crystalline Structure-Dependent Mechanical and Thermoelectric Performance in Ag_(2)Se_(1‐x)S_(x)System

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Research 2020年第1期2020卷 1089-1098页

作者： jiasheng Liang Pengfei Qiu Yuan Zhu Hui Huang Zhiqiang Gao Zhen Zhang Xun Shi Lidong chen State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Division of Solid-State Electronics Department of Electrical EngineeringUppsala UniversityUppsalaSweden School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

Self-powered wearable electronics require thermoelectric materials simultaneously with a high dimensionless figure of merit(zT)and good flexibility to convert the heat discharged by the human body into electricity.Ag_(2)(S,Se)-based semiconducting materials can well satisfy these requirements,and thus,they are attracting great attention in thermoelectric society recently.Ag_(2)(S,Se)crystalizes in an orthorhombic structure or monoclinic structure,depending on the detailed S/Se atomic ratio,but the relationship between its crystalline structure and mechanical/thermoelectric performance is still unclear to date.In this study,a series of Ag_(2)Se_(1-x)S_(x)(x=0,0.1,0.2,0.3,0.4,and 0.45)samples were prepared and their mechanical and thermoelectric performance dependence on the crystalline structure was systematically investigated.x=0:3 in the Ag_(2)Se_(1-x)S_(x)system was found to be the transition boundary between orthorhombic and monoclinic structures.Mechanical property measurement shows that the orthorhombic Ag_(2)Se_(1-x)S_(x)samples are brittle while the monoclinic Ag_(2)Se_(1-x)S_(x)samples are ductile and flexible.In addition,the orthorhombic Ag_(2)Se_(1-x)S_(x)samples show better electrical transport performance and higher zT than the monoclinic samples under a comparable carrier concentration,most likely due to their weaker electron-phonon interactions.This study sheds light on the further development of flexible inorganic TE materials.

关键词： ductile crystalline attracting

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