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Preparation of Environmentally Friendly Urea-Hexanediamine-Glyoxal(HUG)Resin Wood Adhesive
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作者 Qianyu Zhang Shi Chen +4 位作者 long cao Hong Lei Antonio Pizzi Xuedong Xi Guanben Du 《Journal of Renewable Materials》 EI CAS 2024年第2期235-244,共10页
Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood industry.However,urea-glyoxal(U... Using non-toxic,low-volatile glyoxal to completely replace formaldehyde for preparing urea-glyoxal(UG)resin adhesive is a hot research topic that could be of great interest for the wood industry.However,urea-glyoxal(UG)resins prepared by just using glyoxal instead of formaldehyde usually yields a lower degree of polymerization.This results in a poorer bonding performance and water resistance of UG resins.A good solution is to pre-react urea to preform polyurea molecules presenting already a certain degree of polymerization,and then to condense these with glyoxal to obtain a novel UG resin.Therefore,in this present work,the urea was reacted with hexamethylene diamine to form a polyurea named HU,and then this was used to react it with different amounts of glyoxal to synthesize hexamethylenediamine-urea-glyoxal(HUG)polycondensation resins,and to use this for bonding plywood.The results show that the glyoxal can well react with HU polyuria via addition and schiff base reaction,and also the HUG resin exhibits excellent bonding strength and water resistance.The shear strength of the plywood bonded with this HUG at 160°C hot press temperature as high as 1.93 MPa,2.16 MPa and 1.61 MPa,respectively,which meets the requirement of the China national standard GB/T 9846-2015(≥0.7 MPa),and can be a good choice as a wood adhesive for industrial application. 展开更多
关键词 Urea-glyoxal resin hexamethylene diamine wood adhesives water resistance
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Effects of solar radiation modification on the ocean carbon cycle:An earth system modeling study 被引量:1
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作者 Xiaoyu Jin long cao Jingyu Zhang 《Atmospheric and Oceanic Science Letters》 CSCD 2022年第3期56-63,共8页
Solar radiation modification(SRM,also termed as geoengineering)has been proposed as a potential option to counteract anthropogenic warming.The underlying idea of SRM is to reduce the amount of sunlight reaching the at... Solar radiation modification(SRM,also termed as geoengineering)has been proposed as a potential option to counteract anthropogenic warming.The underlying idea of SRM is to reduce the amount of sunlight reaching the atmosphere and surface,thus offsetting some amount of global warming.Here,the authors use an Earth system model to investigate the impact of SRM on the global carbon cycle and ocean biogeochemistry.The authors simulate the temporal evolution of global climate and the carbon cycle from the pre-industrial period to the end of this century under three scenarios:the RCP4.5 CO_(2) emission pathway,the RCP8.5 CO_(2) emission pathway,and the RCP8.5 CO_(2) emission pathway with the implementation of SRM to maintain the global mean surface temperature at the level of RCP4.5.The simulations show that SRM,by altering global climate,also affects the global carbon cycle.Compared to the RCP8.5 simulation without SRM,by the year 2100,SRM reduces atmospheric CO_(2) by 65 ppm mainly as a result of increased CO_(2) uptake by the terrestrial biosphere.However,SRM-induced change in atmospheric CO_(2) and climate has a small effect in mitigating ocean acidification.By the year 2100,relative to RCP8.5,SRM causes a decrease in surface ocean hydrogen ion concentration([H^(+)])by 6% and attenuates the seasonal amplitude of[H^(+)]by about 10%.The simulations also show that SRM has a small effect on globally integrated ocean net primary productivity relative to the high-CO_(2) simulation without SRM.This study contributes to a comprehensive assessment of the effects of SRM on both the physical climate and the global carbon cycle. 展开更多
关键词 Solar radiation modification GEOENGINEERING Carbon cycle Ocean acidification Ocean biogeochemistry
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MALDI ToF Investigation of the Reaction of Soy Protein Isolate with Glutaraldehyde for Wood Adhesives 被引量:1
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作者 Qianyu Zhang Antonio Pizzi +3 位作者 Hong Lei Xuedong Xi Ming cao long cao 《Journal of Renewable Materials》 SCIE EI 2023年第3期1439-1450,共12页
Soy protein adhesives are currently a hot research topic in the wood panels industry for the abundant raw material reserves,reasonable price and outstanding environmental features.But their poor water resistance,low b... Soy protein adhesives are currently a hot research topic in the wood panels industry for the abundant raw material reserves,reasonable price and outstanding environmental features.But their poor water resistance,low bonding strength and intolerance to mold are major drawbacks,so that proper modification before use is essential.Glutaraldehyde is one of the more apt cross-linking agents for soybean protein adhesives,which can effectively improve the bonding strength and water resistance of the adhesive.Equally,glutaraldehyde is also an efficient and broad-spectrum fungicide that can significantly improve the anti-fungal properties of a soy protein adhesive.In the work presented here,matrix assisted laser desorption ionization(MALDI-ToF)mass spectrometry and Fourier transform infrared spectroscopy techniques were used to analyze the reaction mechanism of glutaraldehyde cross-linking soybean protein.The results confirmed the reaction of the aldehyde group with amino groups of the side chains and the amide groups of the peptide linkages constituting the skeletal chain of the protein.The laboratory plywood and particleboard bonded with glutaraldehyde-soy bean protein adhesives were prepared to determine the adhesive bonding properties,the dry strength,24 h cold water soaking wet strength and 3 h hot water(63°C)wet strength of plywood were 2.03,1.13 and 0.75 MPa,respectively,which satisfied the requirements of industrial production. 展开更多
关键词 Bio-based adhesives soy bean protein MALDI-TOF PARTICLEBOARD PLYWOOD
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Saphenous graft on transesophageal echocardiogram masquerading as an abnormal vascular communication into the right atrium
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作者 long cao Mohammed Ataullah Farooqui +2 位作者 William Wood John Cahill Assad Movahed 《World Journal of Clinical Cases》 SCIE 2013年第1期28-30,共3页
An unknown aberrant f low in the right atrium observed on doppler with transesophageal echocardiogram(TEE) in a patient with prior coronary bypass. TEE revealed normal size left ventricle with severely dilated left at... An unknown aberrant f low in the right atrium observed on doppler with transesophageal echocardiogram(TEE) in a patient with prior coronary bypass. TEE revealed normal size left ventricle with severely dilated left atrium. There was moderate aortic regurgitation and moderate aortic stenosis noted. Patient was incidentally found to have an abnormal vascular communication noted to the right atrium. To further evaluate this f inding, the patient underwent cardiac magnetic resonance angiography which revealed that the tubular structure noted on TEE was actually a graft that was abutting onto the coronary sinus, and the f low anomaly was really the graft coming up and running adjacent to the coronary sinus. 展开更多
关键词 VASCULAR COMMUNICATION ECHOCARDIOGRAM Saphenous VEIN GRAFT Magnetic resonance imaging
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DB-DCAFN:dual-branch deformable cross-attention fusion network for bacterial segmentation
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作者 Jingkun Wang Xinyu Ma +6 位作者 long cao Yilin Leng Zeyi Li Zihan Cheng Yuzhu cao Xiaoping Huang Jian Zheng 《Visual Computing for Industry,Biomedicine,and Art》 EI 2023年第1期155-170,共16页
Sputum smear tests are critical for the diagnosis of respiratory diseases. Automatic segmentation of bacteria from spu-tum smear images is important for improving diagnostic efficiency. However, this remains a challen... Sputum smear tests are critical for the diagnosis of respiratory diseases. Automatic segmentation of bacteria from spu-tum smear images is important for improving diagnostic efficiency. However, this remains a challenging task owing to the high interclass similarity among different categories of bacteria and the low contrast of the bacterial edges. To explore more levels of global pattern features to promote the distinguishing ability of bacterial categories and main-tain sufficient local fine-grained features to ensure accurate localization of ambiguous bacteria simultaneously, we propose a novel dual-branch deformable cross-attention fusion network (DB-DCAFN) for accurate bacterial segmen-tation. Specifically, we first designed a dual-branch encoder consisting of multiple convolution and transformer blocks in parallel to simultaneously extract multilevel local and global features. We then designed a sparse and deformable cross-attention module to capture the semantic dependencies between local and global features, which can bridge the semantic gap and fuse features effectively. Furthermore, we designed a feature assignment fusion module to enhance meaningful features using an adaptive feature weighting strategy to obtain more accurate segmentation. We conducted extensive experiments to evaluate the effectiveness of DB-DCAFN on a clinical dataset comprising three bacterial categories: Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The experi-mental results demonstrate that the proposed DB-DCAFN outperforms other state-of-the-art methods and is effective at segmenting bacteria from sputum smear images. 展开更多
关键词 Bacterial segmentation Dual-branch parallel encoder Deformable cross-attention module Feature assignment fusion module
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猕猴脑网络组图谱:包含分区、连接和组织学的多层面全新大脑地图
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作者 陆玉恒 崔玥 +31 位作者 曹龙 董振伟 程禄祺 吴雯 王昌硕 刘新异 刘有通 张宝贵 李德莹 赵舶凯 王海艳 李开心 马亮 时维阳 李雯 马亚伟 杜宗昌 张佳琪 熊辉 罗娜 刘妍妍 侯肖逍 韩景路 孙洪吉 蔡涛 彭强 冯琳清 王骄健 George Paxinos 杨正宜 樊令仲 蒋田仔 《Science Bulletin》 SCIE EI CAS CSCD 2024年第14期2241-2259,共19页
The rhesus macaque(Macaca mulatta)is a crucial experimental animal that shares many genetic,brain organizational,and behavioral characteristics with humans.A macaque brain atlas is fundamental to biomedical and evolut... The rhesus macaque(Macaca mulatta)is a crucial experimental animal that shares many genetic,brain organizational,and behavioral characteristics with humans.A macaque brain atlas is fundamental to biomedical and evolutionary research.However,even though connectivity is vital for understanding brain functions,a connectivity-based whole-brain atlas of the macaque has not previously been made.In this study,we created a new whole-brain map,the Macaque Brainnetome Atlas(MacBNA),based on the anatomical connectivity profiles provided by high angular and spatial resolution ex vivo diffusion MRI data.The new atlas consists of 248 cortical and 56 subcortical regions as well as their structural and functional connections.The parcellation and the diffusion-based tractography were evaluated with invasive neuronal-tracing and Nissl-stained images.As a demonstrative application,the structural connectivity divergence between macaque and human brains was mapped using the Brainnetome atlases of those two species to uncover the genetic underpinnings of the evolutionary changes in brain structure.The resulting resource includes:(1)the thoroughly delineated Macaque Brainnetome Atlas(MacBNA),(2)regional connectivity profiles,(3)the postmortem high-resolution macaque diffusion and T2-weighted MRI dataset(Brainnetome-8),and(4)multi-contrast MRI,neuronal-tracing,and histological images collected from a single macaque.MacBNA can serve as a common reference frame for mapping multifaceted features across modalities and spatial scales and for integrative investigation and characterization of brain organization and function.Therefore,it will enrich the collaborative resource platform for nonhuman primates and facilitate translational and comparative neuroscience research. 展开更多
关键词 Macaca mulatta Brain atlas Connectivity-based parcellation Diffusion MRI CYTOARCHITECTURE Cross-species comparison
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Response of ocean acidification to atmospheric carbon dioxide removal
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作者 Jiu Jiang long cao +4 位作者 Xiaoyu Jin Zechen Yu Han Zhang Jianjie Fu Guibin Jiang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第6期79-90,共12页
Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate change.Here we use an Earth system model to examine ... Artificial CO_(2)removal from the atmosphere(also referred to as negative CO_(2)emissions)has been proposed as a potential means to counteract anthropogenic climate change.Here we use an Earth system model to examine the response of ocean acidification to idealized atmospheric CO_(2)removal scenarios.In our simulations,atmospheric CO_(2)is assumed to increase at a rate of 1%per year to four times its pre-industrial value and then decreases to the pre-industrial level at a rate of 0.5%,1%,2%per year,respectively.Our results show that the annual mean state of surface ocean carbonate chemistry fields including hydrogen ion concentration([H^(+)]),pH and aragonite saturation state respond quickly to removal of atmospheric CO_(2).However,the change of seasonal cycle in carbonate chemistry lags behind the decline in atmospheric CO_(2).When CO_(2)returns to the pre-industrial level,over some parts of the ocean,relative to the pre-industrial state,the seasonal amplitude of carbonate chemistry fields is substantially larger.Simulation results also show that changes in deep ocean carbonate chemistry substantially lag behind atmospheric CO_(2)change.When CO_(2)returns to its pre-industrial value,the whole-ocean acidity measured by[H^(+)]is 15%-18%larger than the pre-industrial level,depending on the rate of CO_(2)decrease.Our study demonstrates that even if atmospheric CO_(2)can be lowered in the future as a result of net negative CO_(2)emissions,the recovery of some aspects of ocean acidification would take decades to centuries,which would have important implications for the resilience of marine ecosystems. 展开更多
关键词 Carbon dioxide removal Net negative CO_(2)emission Ocean acidification Climate change Earth system modeling
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Fine-Grained Topography and Modularity of the Macaque Frontal Pole Cortex Revealed by Anatomical Connectivity Profiles 被引量:4
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作者 Bin He long cao +5 位作者 Xiaoluan Xia Baogui Zhang Dan Zhang Bo You Lingzhong Fan Tianzi Jiang 《Neuroscience Bulletin》 SCIE CAS CSCD 2020年第12期1454-1473,共20页
The frontal pole cortex(FPC)plays key roles in various higher-order functions and is highly developed in non-human primates.An essential missing piece of information is the detailed anatomical connections for finer pa... The frontal pole cortex(FPC)plays key roles in various higher-order functions and is highly developed in non-human primates.An essential missing piece of information is the detailed anatomical connections for finer parcellation of the macaque FPC than provided by the previous tracer results.This is important for understanding the functional architecture of the cerebral cortex.Here,combining cross-validation and principal component analysis,we formed a tractography-based parcellation scheme that applied a machine learning algorithm to divide the macaque FPC(2 males and 6 females)into eight subareas using high-resolution diffusion magnetic resonance imaging with the 9.4 T Bruker system,and then revealed their subregional connections.Furthermore,we applied improved hierarchical clustering to the obtained parcels to probe the modular structure of the subregions,and found that the dorsolateral FPC,which contains an extension to the medial FPC,was mainly connected to regions of the default-mode network.The ventral FPC was mainly involved in the social-interaction network and the dorsal FPC in the metacognitive network.These results enhance our understanding of the anatomy and circuitry of the macaque brain,and contribute to FPC-related clinical research. 展开更多
关键词 MACAQUE Frontal pole cortex Anatomical connectivity profile PARCELLATION NEUROIMAGING Principal component analysis
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Ninety cases of simple obesity treated with the combined therapy of penetration needling, flash-fire cupping method and auricular acupuncture 被引量:4
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作者 Juan WANG Yan LI +5 位作者 Xuan ZHANG Mei-na WANG long cao Na NU Yuan LI Gui-lan LI 《World Journal of Acupuncture-Moxibustion》 CSCD 2018年第4期287-290,313-314,共5页
Objective: To observe the clinical effects on simple obesity treated with the combined therapy of penetration needling, flash-fire cupping method and auricular acupuncture.Methods: In 90 patients of simple obesity, th... Objective: To observe the clinical effects on simple obesity treated with the combined therapy of penetration needling, flash-fire cupping method and auricular acupuncture.Methods: In 90 patients of simple obesity, the Bo’s abdominal acupuncture therapy was adopted. Taking Shénquè(神阙 CV 8), the points 2 cun directly below CV 8 and 2 cun directly above CV 8 as the landmarks, 3 cun bilateral to each of the above three points, and penetrated through to the conception vessel. Then the electroacupuncture apparatus was connected, with the disperse-dense wave for 30 min.After acupuncture, the glass cup of the middle size was used to stimulate the selected points with the flash-fire cupping method. The cupping stimulation stopped when the skin turned to be slightly red. One treatment was given each day and every other day after 5 days. The 10 treatments made one course. In the auricular acupuncture therapy, Jīdiǎn(饥点), Shénm6 n(神门TF4), NèiFēnmì(内分泌CO18) and S5 njiāo(三焦 CO17) were selected. The auricular acupuncture therapy was given once every two days and 10 treatments made one course. After 3 courses of treatment, the waist circumference, hip circumference,body weight and body mass index(BMI) were observed.Results: Compared to before treatment, after 3 courses of treatment, the waist circumference of patients was(92.3 ±2.4 vs 80.4 ±2.3) cm, hip circumference(110.6 士 2.3 vs 99.2 ±2.5) cm, body weight(74.2 ±3.1 vs 68.2 ±2.4) kg and BMI(29.8 士 3.1 vs 25.2 士 2.1), they were all reduced obviously, indicating the significant differences(all P<0.05). Seventy-nine patients lost three to five kilograms, accounting for 87.8%.Conclusion: The combined therapy of penetration needling at abdomen, flash-fire cupping method and auricular acupuncture achieves the significant therapeutic effects on simple obesity. 展开更多
关键词 Simple obesity Penetration needling Abdominal needle therapy CUPPING Auricular acupuncture therapy
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Simulated effect of sunshade solar geoengineering on the global carbon cycle 被引量:2
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作者 Jiu JIANG Han ZHANG long cao 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第9期1306-1315,共10页
Solar geoengineering has been proposed as a potential mechanism to counteract global wanning. Here we use the University of Victoria Earth System Model (UVic) to simulate the effect of idealized sunshade geoengineer... Solar geoengineering has been proposed as a potential mechanism to counteract global wanning. Here we use the University of Victoria Earth System Model (UVic) to simulate the effect of idealized sunshade geoengineering on the global carbon cycle. We conduct two simulations. The first is the A2 simulation, where the model is driven by prescribed emission scenario based on the SRES A2 COz emission pathway. The second is the solar geoengineering simulation in which the model is driven by the A2 CO2 emission scenario combined with sunshade solar geoengineering. In the model, solar geoengineering is represented by a spatially uniform reduction in solar insolation that is implemented at year 2020 to offset CO2-induced global mean surface temperature change. Our results show that solar geoengineering increases global carbon uptake relative to A2, in particular CO2 uptake by the terrestrial biosphere. The increase in land carbon uptake is mainly associated with increased net primary production (NPP) in the tropics in the geoengineering simulation, which prevents excess warming in tropics. By year 2100, solar geoengineering decreases A2-simulated atmospheric CO2 by 110 ppm (12%) and causes a 60% (251 Pg C) increase in land carbon accumulation compared to A2. Solar geoengineering also prevents the reduction in ocean oxygen concentration caused by increased ocean temperatures and decreased ocean ventilation, but reduces global ocean NPE Our results suggest that to fully access the climate effect of solar geoengineering, the response of the global carbon cycle should be taken into account. 展开更多
关键词 Solar geoengineering Carbon cycle Climate change Ocean biogeochemistry
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Simulated carbon cycle and Earth system response to atmospheric CO_(2)removal 被引量:1
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作者 long cao Xiao-Yu JIN Jiu JIANG 《Advances in Climate Change Research》 SCIE CSCD 2023年第2期313-321,共9页
To project possible future climate change,it is important to understand Earth system response to CO_(2)removal,a potential key method to limit global warming.Previous studies examined some aspects of Earth system resp... To project possible future climate change,it is important to understand Earth system response to CO_(2)removal,a potential key method to limit global warming.Previous studies examined some aspects of Earth system response to different scenarios of CO_(2)removal,but lacked a systematic analysis of the carbon cycle and climate system response in a consistent modeling framework.We expanded previous studies by using an Earth system model to examine the response of land and ocean carbon cycle,as well as a set of climate variables to idealized scenarios of atmospheric CO_(2)removal with different removal rates.In the scenarios considered,atmospheric CO_(2)increases at a rate of 1%per year to four times of its preindustrial level,and then decreases at a rate of 0.5%,1%,and 2%per year to the preindustrial level.Simulation results show that a reduction of atmospheric CO_(2)induces CO_(2)release from both the ocean and terrestrial biosphere,and to keep atmospheric CO_(2)at a lower level requires the removal of anthropogenic CO_(2)not only from the atmosphere,but from the ocean and land carbon reservoirs as well.The response of many variables of the Earth system,including temperature,ocean heat content,sea level,deep ocean acidity,and permafrost area and carbon,lags the decrease in atmospheric CO_(2)ranging from a few years to many centuries.A few centuries after atmospheric CO_(2)returns to the preindustrial level,sea level is still substantially higher than the preindustrial level,and permafrost continues losing CO_(2)to the atmosphere.Our study demonstrates that to offset previous positive CO_(2)emissions by atmospheric CO_(2)removal does not mean to offset climate consequence of positive CO_(2)emissions.Rapid and deep reduction in CO_(2)emissions is key to prevent and limit increasing risks from further warming.Our study provides new insights into the carbon cycle and climate system response to CO_(2)removal,which would help to assess future climate change and the associated impacts. 展开更多
关键词 CO_(2)emission CO_(2)concentration Atmospheric CO_(2)removal Earth system model Climate change
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An Attenuated Highly Pathogenic Chinese PRRS Viral Vaccine Confers Cross Protection to Pigs against Challenge with the Emerging PRRSV NADC30-Like Strain 被引量:1
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作者 Hewei Zhang Mingqi Xia +10 位作者 Wei Wang Decai Ju long cao Bai Wu Xin Wang Ying Wu Ni Song Jiaxin Hu Changxiao Tian Shucheng Zhang Hua Wu 《Virologica Sinica》 SCIE CAS CSCD 2018年第2期153-161,共9页
A novel PRRSV strain was isolated in China that was genetically similar to the NADC30 strain which is reported to have spread throughout China. The objective of the present study was to evaluate the cross-protective e... A novel PRRSV strain was isolated in China that was genetically similar to the NADC30 strain which is reported to have spread throughout China. The objective of the present study was to evaluate the cross-protective efficacy of the live vaccine TJM-F92 in young pigs against challenge with a NADC30-like strain, HN201605. Twenty-five PRRSV-and antibody-free pigs were randomly divided into the following five groups: Vac/ChA, Unvac/ChA, Vac/ChB, Unvac/ChB and the mock.The pigs in groups Vac/ChA and Vac/ChB were inoculated intramuscularly with 1 mL TJM-F92(10^(5.0) TCID_(50)/mL). At28 days post vaccination(0 days post challenge), groups Vac/ChA and Unvac/ChA were inoculated intranasally with 10^(4.5) TCID_(50)/mL PRRSV strain TJ F3(2 mL/pig), while groups Vac/ChB and Unvac/Ch B were inoculated, using the same route, with the same dose of the NADC30-like strain HN201605 F3. Protective effects of the PRRSV strain were observed in all pigs in the Vac/ChA and Vac/ChB groups. Neither high fever nor signs of clinical disease were observed through the experiment in these groups, whereas pigs in Unvac/ChA group exhibited serious clinical symptoms, pathological lesions,and weight loss. In Unvac/ChB group, pigs developed milder clinical symptoms, which demonstrated that the NADC30-like strain HN201605 had moderate pathogenicity. The results suggest that the MLV vaccine strain TJM-F92 is an effective and safe vaccine candidate for use in China. 展开更多
关键词 Porcine reproductive and respiratory syndrome virus (PRRSV) NADC30-like VACCINE Cross protection
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Comparison of the carbon cycle and climate response to artificial ocean alkalinization and solar radiation modification
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作者 Xiao-Yu JIN long cao 《Advances in Climate Change Research》 SCIE CSCD 2023年第2期322-334,共13页
Carbon dioxide removal and solar radiation modification(SRM)are two classes of proposed climate intervention methods.A thorough understanding of climate system response to these methods calls for a good understanding ... Carbon dioxide removal and solar radiation modification(SRM)are two classes of proposed climate intervention methods.A thorough understanding of climate system response to these methods calls for a good understanding of the carbon cycle response.In this study,we used an Earth system model to examine the response of global climate and carbon cycle to artificial ocean alkalinization(AOA),a method of CO_(2)removal,and reduction in solar irradiance that represents the overall effect of solar radiation modification.In our simulations,AOA is applied uniformly over the global ice-free ocean under the RCP8.5 scenario to bring down atmospheric CO_(2)to the level of RCP4.5,and SRM is applied uniformly over the globe under the RCP8.5 scenario to bring down global mean surface temperature to the level of RCP4.5.Our simulations show that with the same goal of temperature stabilization,AOA and SRM cause fundamentally different perturbations of the ocean and land carbon cycle.By the end of the 21st century,relative to the simulation of RCP8.5,AOA-induced changes in ocean carbonate chemistry enhances global oceanic CO_(2)uptake by 983 PgC and increases global mean surface ocean pH by 0.42.Meanwhile,AOA reduces land CO_(2)uptake by 79 PgC and reduces atmospheric CO_(2)concentration by 426×10^(−6).By contrast,relative to the simulation of RCP8.5,SRM has a minor effect on the oceanic CO_(2)uptake and ocean acidification.SRM-induced cooling enhances land CO_(2)uptake by 140 PgC and reduces atmospheric CO_(2)concentration by 63×10^(−6).A sudden termination of SRM causes a rate of temperature change that is much larger than that of RCP8.5.A sudden termination of AOA causes a rate of temperature change that is comparable to that of RCP8.5 and a rate of ocean acidification that is much larger than that of RCP8.5. 展开更多
关键词 Carbon dioxide removal Solar radiation modification GEOENGINEERING Carbon cycle Ocean acidification
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Simulated effects of interactions between ocean acidification,marine organism calcification, and organic carbon export on ocean carbon and oxygen cycles
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作者 Han ZHANG long cao 《Science China Earth Sciences》 SCIE EI CAS CSCD 2018年第6期804-822,共19页
Ocean acidification caused by oceanic uptake of anthropogenic carbon dioxide(CO_2) tends to suppress the calcification of some marine organisms. This reduced calcification then enhances surface ocean alkalinity and in... Ocean acidification caused by oceanic uptake of anthropogenic carbon dioxide(CO_2) tends to suppress the calcification of some marine organisms. This reduced calcification then enhances surface ocean alkalinity and increases oceanic CO_2 uptake, a process that is termed calcification feedback. On the other hand, decreased calcification also reduces the export flux of calcium carbonate(Ca CO_3), potentially reducing Ca CO_3-bound organic carbon export flux and CO_2 uptake, a process that is termed ballast feedback. In this study, we incorporate a range of different parameterizations of the links between organic carbon export, calcification, and ocean acidification into an Earth system model, in order to quantify the long-term effects on oceanic CO_2 uptake that result from calcification and ballast feedbacks. We utilize an intensive CO_2 emission scenario to drive the model in which an estimated fossil fuel resource of 5000 Pg C is burnt out over the course of just a few centuries. Simulated results show that, in the absence of both calcification and ballast feedbacks, by year 3500, accumulated oceanic CO_2 uptake is2041 Pg C. Inclusion of calcification feedback alone increases the simulated uptake by 629 Pg C(31%), while the inclusion of both calcification and ballast feedbacks increase simulated uptake by 449–498 Pg C(22–24%), depending on the parameter values used in the ballast feedback scheme. These results indicate that ballast effect counteracts calcification effect in oceanic CO_2 uptake. Ballast effect causes more organic carbon to accumulate and decompose in the upper ocean, which in turn leads to decreased oxygen concentration in the upper ocean and increased oxygen at depths. By year 2600, the inclusion of ballast effect would decrease oxygen concentration by 11% at depth of ca. 200 m in tropics. Our study highlights the potentially critical effects of interactions between ocean acidification, marine organism calcification, and Ca CO3-bound organic carbon export on the ocean carbon and oxygen cycles. 展开更多
关键词 Ocean carbon cycle Ocean acidification Carbon cycle modeling Carbon cycle-climate feedback
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