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Probing signals of atmospheric gravity waves excited by the July 29,2021 M_(W)8.2 Alaska earthquake
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作者 Geng Zhang Jianqiao Xu +2 位作者 xiaodong chen Heping Sun Lizhuo Gong 《Geodesy and Geodynamics》 EI CSCD 2024年第3期219-229,共11页
It is commonly believed that the atmosphere is decoupled from the solid Earth.Thus,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals ex... It is commonly believed that the atmosphere is decoupled from the solid Earth.Thus,it is difficult for the seismic wave energy inside the Earth to propagate into the atmosphere,and atmospheric pressure wave signals excited by earthquakes are unlikely to exist in atmospheric observations.An increasing number of studies have shown that earthquakes,volcanoes,and tsunamis can perturb the Earth's atmosphere due to various coupling effects.However,the observations mainly focus on acoustic waves with periods of less than 10 min and inertial gravity waves with periods of greater than 1 h.There are almost no clear observations of gravity waves that coincide with observations of low-frequency signals of the Earth's free oscillation frequency band within 1 h.This paper investigates atmospheric gravity wave signals within1 h of surface-atmosphere observations using the periodogram method based on seismometer and microbarometer observations from the global seismic network before and after the July 29,2021 M_(w)8.2 Alaska earthquake in the United States.The numerical results show that the atmospheric gravity wave signals with frequencies similar to those of the Earth's free oscillations _(0)S_(2) and _(0)T_(2) can be detected in the microbaro meter observations.The results con firm the existence of atmospheric gravity waves,indicating that the atmosphere and the solid Earth are not decoupled within this frequency band and that seismic wave energy excited by earthquakes can propagate from the interior of the Earth to the atmosphere and enhance the atmospheric gravity wave signals within 1 h. 展开更多
关键词 Atmospheric gravity modes Atmospheric gravity waves Alaska earthquake Normal modes Coupling of solid earth and atmosphere
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Impact of Air Pollutants on Lung Function and Inflammatory Response in Asthma in Shanghai
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作者 Guifang Wang Youzhi Zhang +6 位作者 Haiyan Yang Yi Yang Liang Dong Peng Zhang Jie Liu xiaodong chen Yi Gong 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第8期811-822,共12页
Objective Air pollution is a leading public health issue.This study investigated the effect of air quality and pollutants on pulmonary function and inflammation in patients with asthma in Shanghai.Methods The study mo... Objective Air pollution is a leading public health issue.This study investigated the effect of air quality and pollutants on pulmonary function and inflammation in patients with asthma in Shanghai.Methods The study monitored 27 asthma outpatients for a year,collecting data on weather,patient self-management[daily asthma diary,peak expiratory flow(PEF)monitoring,medication usage],spirometry and serum markers.To explore the potential mechanisms of any effects,asthmatic mice induced by ovalbumin(OVA)were exposed to PM_(2.5).Results Statistical and correlational analyses revealed that air pollutants have both acute and chronic effects on asthma.Acute exposure showed a correlation between PEF and levels of ozone(O_(3))and nitrogen dioxide(NO_(2)).Chronic exposure indicated that interleukin-5(IL-5)and interleukin-13(IL-13)levels correlated with PM_(2.5)and PM_(10)concentrations.In asthmatic mouse models,exposure to PM_(2.5)increased cytokine levels and worsened lung function.Additionally,PM_(2.5)exposure inhibited cell proliferation by blocking the NF-κB and ERK phosphorylation pathways.Conclusion Ambient air pollutants exacerbate asthma by worsening lung function and enhancing Th2-mediated inflammation.Specifically,PM_(2.5)significantly contributes to these adverse effects.Further research is needed to elucidate the mechanisms by which PM_(2.5)impacts asthma. 展开更多
关键词 Ambient air pollutants Acute and chronic effects on asthma PM_(2.5) OVA-induced asthmatic mice
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Alcoholic and Non-Alcoholic Marchiafava-Bignami Disease: A Comparative Study
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作者 xiaodong chen Yuanwei Wang +2 位作者 Ying Wang Daoming Tong Baolin Zhu 《Neuroscience & Medicine》 2016年第3期99-105,共7页
Purpose: Marchiafava-Bignami Disease (MBD) is a rare condition mainly associated with alcoholism, although a few non-alcoholic cases have been reported. We performed a comparative study of demographic and clinical dif... Purpose: Marchiafava-Bignami Disease (MBD) is a rare condition mainly associated with alcoholism, although a few non-alcoholic cases have been reported. We performed a comparative study of demographic and clinical differences between alcoholic and non-alcoholic and assessed whether any treatment can be recommended. Methods: We reviewed 157 reports containing data on 168 subjects with Alcoholic MBD (AMBD) and 23 subjects with Non-Alcoholic MBD (NAMBD). The following data were extracted: demographic characteristics;delay from the onset of symptoms to admission;MRI features;location of the corpus callosum lesions;the presence of Wernicke’s disease;drug treatment (thiamine, other vitamins and steroids);outcome. Results: The subjects with AMBD were more frequently men (84.5% vs 47.8, P = 0.000);the ones with AMBD were frequently reported as suffering from malnutrition (81.3% vs 50%, P = 0.019), whereas the NAMBD was frequently reported as suffering from diabetes mellitus (30.4% vs 7.1%, P = 0.002). The lesions in the NAMBD are often located in the splenium (47.8%), whereas single splenial lesions are seen only in 18.7% of the AMBD. 43.5% (10/23) of the NAMBD was reported to have recovered completely, whereas only 15.4% (24/156) AMBD showed a complete recovery. Conclusions: It is important to diagnose NAMBD in the early stage with MRI and to treat the symptoms with thiamine and/or corticosteroids according to aetiology. We recommend prompt treatment of MBD with parenteral thiamine in subjects associated with malnutrition, anorexia nervosa and prolonged vomiting, and reduction of food intake. Corticosteroids may aid in recovery by reducing oedema in subjects associated with diabetes mellitus. 展开更多
关键词 Marchiafava-Bignami Disease ALCOHOLISM MALNUTRITION Diabetes Mellitus PROGNOSIS
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Mesenchymal stem cells: a new strategy for immunosuppression and tissue repair 被引量:75
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作者 Yufang Shi Gangzheng Hu +11 位作者 Juanjuan Su Wenzhao Li Qing chen Peishun Shou Chunliang Xu xiaodong chen Yin Huang Zhexin Zhu Xin Huang Xiaoyan Han Ningxia Xie Guangwen Ren 《Cell Research》 SCIE CAS CSCD 2010年第5期510-518,共9页
Mesenchymal stem cells (MSCs) have great potential for treating various diseases, especially those related to tissue damage involving immune reactions. Various studies have demonstrated that MSCs are strongly immuno... Mesenchymal stem cells (MSCs) have great potential for treating various diseases, especially those related to tissue damage involving immune reactions. Various studies have demonstrated that MSCs are strongly immunosuppressive in vitro and in vivo. Our recent studies have shown that un-stimulated MSCs are indeed incapable of immunosuppression; they become potently immunosuppressive upon stimulation with the supernatant of activated lymphocytes, or with combinations of IFN-γ, with TNF-α, IL-1α or IL-1β. This observation revealed that under certain circumstances, inflammatory cytokines can actually become immunosuppressive. We showed that there is a species variation in the mechanisms of MSC-mediated immunosuppression: immunosuppression by cytokine-primed mouse MSCs is mediated by nitric oxide (NO), whereas immunosuppression by cytokine-primed human MSCs is executed through indoleamine 2, 3-dioxygenase (IDO). Additionally, upon stimulation with the inflammatory cytokines, both mouse and human MSCs secrete several leukocyte chemokines that apparently serve to attract immune cells into the proximity with MSCs, where NO or IDO is predicted to be most active. Therefore, immunosuppression by inflammatory cytokine-stimulated MSCs occurs via the concerted action of chemokines and immune-inhibitory NO or IDO produced by MSCs. Thus, our results provide novel information about the mechanisms of MSC-mediated immunosuppression and for better application of MSCs in treating tissue injuries induced by immune responses. 展开更多
关键词 MSCS IMMUNOSUPPRESSION tissue repair immune diseases
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Changes in the gut microbiota mediate the differential regulatory effects of two glucose oxidases produced by Aspergillus niger and Penicillium amagasakiense on the meat quality and growth performance of broilers 被引量:8
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作者 Shengru Wu xiaodong chen +3 位作者 Taohuan Li Hao Ren Lixin Zheng Xiaojun Yang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2020年第4期1232-1244,共13页
Background: Glucose oxidase(GOD), an aerobic dehydrogenase, has been used as an antibiotic substitute in feed.A study was conducted to evaluate the differential effects of 2 different GODs fermented by Aspergillus nig... Background: Glucose oxidase(GOD), an aerobic dehydrogenase, has been used as an antibiotic substitute in feed.A study was conducted to evaluate the differential effects of 2 different GODs fermented by Aspergillus niger or Penicillium amagasakiense on caecal microbiota and to further illuminate the potential roles of changes in the gut microbiota in regulating the growth performance and meat quality of broiler chickens.Results: A total of 420 one-day-old healthy Arbor Acres broilers were randomly assigned to 4 treatments: the control group,the antibiotic growth promoter(AGP) supplementation group, and the GOD-A and GOD-P(GODs produced by A. niger and P. amagasakiense, respectively) groups. As a result, supplementation with GOD produced by P. amagasakiense could significantly improve the average daily weight gain and average daily feed intake of broilers before 21 days of age by significantly increasing the enzymatic activities of jejunal amylase and those of ileal amylase, chymotrypsin, and lipase in21-day-old broilers and could increase the enzymatic activities of duodenal amylase, jejunal amylase and lipase, and ileal chymotrypsin and lipase in 42-day-old broilers. Meanwhile, compared with AGP treatment, supplementation with GOD produced by P. amagasakiense significantly decreased the L value of 21-day-old broilers and the Δp H and L* value of 42-day-old broilers, while supplementation with GOD produced by A. niger significantly increased the p H24 hvalue of 21-day-old and 42-day-old broilers by reducing plasma malondialdehyde content. By using 16 S r RNA sequencing, we found that the beneficial bacteria and microbiota in broilers were not disturbed but were improved by GOD supplementation compared with ADP treatment, including the genera Eubacterium and Christensenel a and the species uncultured_Eubacterium_sp,Clostridium_asparagiforme, and uncultured_Christensenel a_sp, which were positively related to the improved intestinal digestive enzymatic activities, growth performance, and meat quality of broilers.Conclusion: The altered gut microbiota induced by supplementation with glucose oxidase produced by P. amagasakiense mediate better regulatory effects on the meat quality and growth performance of broilers than that induced by supplementation with glucose oxidase produced by A. niger. 展开更多
关键词 BROILER Glucose oxidase Growth performance Gut function Gut microbiota
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Identification of relevant active sites and a mechanism study for reverse water gas shift reaction over Pt/CeO_2 catalysts 被引量:7
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作者 xiaodong chen Xiong Su +5 位作者 Binglian Liang Xiaoli Yang Xinyi Ren Hongmin Duan Yanqiang Huang Tao Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2016年第6期1051-1057,共7页
Reverse water gas shift (RWGS) reaction can serve as a pivotal stage in the CO2 conversion processes, which is vital for the utilization of CO2. In this study, RWGS reaction was performed over Pt/CeO2 catalysts at the... Reverse water gas shift (RWGS) reaction can serve as a pivotal stage in the CO2 conversion processes, which is vital for the utilization of CO2. In this study, RWGS reaction was performed over Pt/CeO2 catalysts at the temperature range of 200-500 degrees C under ambient pressure. Compared with pure CeO2, Pt/CeO2 catalysts exhibited superior RWGS activity at lower reaction temperature. Meanwhile, the calculated TOF and E-a values are approximately the same over these Pt/CeO2 catalysts pretreated under various calcination conditions, indicating that the RWGS reaction is not affected by the morphologies of anchored Pt nanoparticles or the primary crystallinity of CeO2. TPR and XPS results indicated that the incorporation of Pt promoted the reducibility of CeO2 support and remarkably increased the content of Ce 3 + sites on the catalyst surface. Furthermore, the CO TPSR-MS signal under the condition of pure CO2 flow over Pt/CeO 2 catalyst is far lower than that under the condition of adsorbed CO2 with H-2 -assisted flow, revealing that CO2 molecules adsorbed on Ce3+ active sites have difficult in generating CO directly. Meanwhile, the adsorbed CO2 with the assistance of H-2 can form formate species easily over Ce3+ active sites and then decompose into Ce3+-CO species for CO production, which was identified by in-situ FTIR. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B. V. and Science Press. All rights reserved. 展开更多
关键词 RWGS reaction Pt/CeO2 catalyst Formate intermediate MECHANISM
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High rumen degradable starch decreased goat milk fat via trans-10,cis-12 conjugated linoleic acid-mediated downregulation of lipogenesis genes,particularly,INSIG1 被引量:6
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作者 Lixin Zheng Shengru Wu +6 位作者 Jing Shen Xiaoying Han Chunjia Jin xiaodong chen Shengguo Zhao Yangchun Cao Junhu Yao 《Journal of Animal Science and Biotechnology》 CAS CSCD 2020年第3期805-818,共14页
Background:Starch is an important substance that supplies energy to ruminants.To provide sufficient energy for high-yielding dairy ruminants,they are typically fed starch-enriched diets.However,starch-enriched diets h... Background:Starch is an important substance that supplies energy to ruminants.To provide sufficient energy for high-yielding dairy ruminants,they are typically fed starch-enriched diets.However,starch-enriched diets have been proven to increase the risk of milk fat depression(MFD)in dairy cows.The starch present in ruminant diets could be divided into rumen-degradable starch(RDS)and rumen escaped starch(RES)according to their different degradation sites(rumen or intestine).Goats and cows have different sensitivities to MFD.Data regarding the potential roles of RDS in milk fat synthesis in the mammary tissue of dairy goats and in regulating the occurrence of MFD are limited.Results:Eighteen Guanzhong dairy goats(day in milk=185±12 d)with similar parity,weight,and milk yield were selected and randomly assigned to one of three groups(n=6),which were fed an LRDS diet(Low RDS=20.52%),MRDS diet(Medium RDS=22.15%),or HRDS diet(High RDS=24.88%)for 5 weeks.Compared with that of the LRDS group,the milk fat contents in the MRDS and HRDS groups significantly decreased.The yields of short-,mediumand long-chain fatty acids decreased in the HRDS group.Furthermore,increased RDS significantly decreased ruminal B.fibrisolvens and Pseudobutyrivibrio abundances and increased the trans-10,cis-12 conjugated linoleic acid(CLA)and trans-10 C18:1 contents in the rumen fluid.A multiomics study revealed that the HRDS diet affected mammary lipid metabolism down-regulation of ACSS2,MVD,AGPS,SCD5,FADS2,CERCAM,SC5D,HSD17B7,HSD17B12,ATM,TP53RK,GDF1 and LOC102177400.Remarkably,the significant decrease of INSIG1,whose expression was depressed by trans-10,cis-12 CLA,could reduce the activity of SREBP and,consequently,downregulate the downstream gene expression of SREBF1.Conclusions:HRDS-induced goat MFD resulted from the downregulation of genes involved in lipogenesis,particularly,INSIG1.Specifically,even though the total starch content and the concentrate-to-fiber ratio were the same as those of the high-RDS diet,the low and medium RDS diets did not cause MFD in lactating goats. 展开更多
关键词 Dairy goat INSIG1 Milk fat depression Rumen degradable starch Trans-10 cis-12 CLA
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我国城镇居民收入分配机会不平等的生成机制分析:教育的传导作用究竟几何? 被引量:3
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作者 陈晓东 黄晓凤 《教育与经济》 CSSCI 北大核心 2021年第5期39-48,88,共11页
收入分配机会不平等问题备受学界关注,本文从教育中介视角分析我国城镇居民收入分配机会不平等的生成机制。基于Roemer的机会平等理论分析框架及分位数回归方法,使用2013年中国家庭收入调查数据,研究结果表明:(1)我国城镇居民收入分配... 收入分配机会不平等问题备受学界关注,本文从教育中介视角分析我国城镇居民收入分配机会不平等的生成机制。基于Roemer的机会平等理论分析框架及分位数回归方法,使用2013年中国家庭收入调查数据,研究结果表明:(1)我国城镇居民收入分配机会不平等的相对比重约为17.57%,该比重存在较为明显的年龄和性别异质性,且机会不平等在收入分布中具有“左尾”偏向性;(2)收入分配机会不平等通过教育传导的比例约为12.24%,在女性群体中这一比例更高,接近所有传导渠道总和的1/4,通过教育渠道对城镇居民收入分配差距的影响也存在明显的“左尾”偏向性;(3)在教育传导渠道中,教育数量和教育质量所占比重分别为71.60%和28.40%,且在较低收入群体中,教育质量因素所占比重相对更高。本文的政策含义如下:促进社会公平正义需以降低收入分配的机会不平等为目标导向,重要举措之一便是在提高教育回报率的同时降低居民教育获得的机会不平等程度。 展开更多
关键词 机会不平等 传导渠道 教育数量 教育质量 分位数回归
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Multi‑omics reveals that the host‑microbiome metabolism crosstalk of differential rumen bacterial enterotypes can regulate the milk protein synthesis of dairy cows 被引量:2
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作者 chenguang Zhang Mengya Wang +8 位作者 Huifeng Liu Xingwei Jiang xiaodong chen Tao Liu Qingyan Yin Yue Wang Lu Deng Junhu Yao Shengru Wu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第6期2496-2513,共18页
Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolite... Background Dairy cows’lactation performance is the outcome of the crosstalk between ruminal microbial metabo-lism and host metabolism.However,it is still unclear to what extent the rumen microbiome and its metabolites,as well as the host metabolism,contribute to regulating the milk protein yield(MPY).Methods The rumen fluid,serum and milk of 12 Holstein cows with the same diet(45%coarseness ratio),parity(2–3 fetuses)and lactation days(120–150 d)were used for the microbiome and metabolome analysis.Rumen metabolism(rumen metabolome)and host metabolism(blood and milk metabolome)were connected using a weighted gene co-expression network(WGCNA)and the structural equation model(SEM)analyses.Results Two different ruminal enterotypes,with abundant Prevotella and Ruminococcus,were identified as type1 and type2.Of these,a higher MPY was found in cows with ruminal type2.Interestingly,[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae(the differential bacteria)were the hub genera of the network.In addition,differential ruminal,serum and milk metabolome between enterotypes were identified,where the cows with type2 had higher L-tyrosine of rumen,ornithine and L-tryptophan of serum,and tetrahydroneopterin,palmitoyl-L-carnitine,S-lactoylglutathione of milk,which could provide more energy and substrate for MPY.Further,based on the identi-fied modules of ruminal microbiome,as well as ruminal serum and milk metabolome using WGCNA,the SEM analysis indicated that the key ruminal microbial module1,which contains the hub genera of the network([Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae)and high abundance of bacteria(Prevotella and Ruminococcus),could regulate the MPY by module7 of rumen,module2 of blood,and module7 of milk,which contained L-tyrosine and L-tryptophan.Therefore,in order to more clearly reveal the process of rumen bacterial regulation of MPY,we established the path of SEM based on the L-tyrosine,L-tryptophan and related components.The SEM based on the metabolites suggested that[Ruminococcus]gauvreauii group could inhibit the energy supply of serum tryptophan to MPY by milk S-lactoylglutathione,which could enhance pyruvate metabolism.Norank_f_Ruminococcaceae could increase the ruminal L-tyrosine,which could provide the substrate for MPY.Conclusion Our results indicated that the represented enterotype genera of Prevotella and Ruminococcus,and the hub genera of[Ruminococcus]gauvreauii group and norank_f_Ruminococcaceae could regulate milk protein synthesis by affecting the ruminal L-tyrosine and L-tryptophan.Moreover,the combined analysis of enterotype,WGCNA and SEM could be used to connect rumen microbial metabolism with host metabolism,which provides a fundamental understanding of the crosstalk between host and microorganisms in regulating the synthesis of milk composition. 展开更多
关键词 Dairy cows Microbial and host metabolome Milk protein Ruminal microbiota enterotype Structural equation model Weighted gene co-expression network
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A functional hyperbranched binder enabling ultra-stable sulfur cathode for high-performance lithium-sulfur battery 被引量:2
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作者 Xiang Luo Xianbo Lu +5 位作者 xiaodong chen Ya chen Chunyang Yu Dawei Su Guoxiu Wang Lifeng Cui 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第11期63-72,共10页
Binders are of vital importance in stabilizing the cathodes to enhance the cycling stability of lithiumsulfur(Li-S) batteries. However, conventional binders are typically confronted with the drawback of inability for ... Binders are of vital importance in stabilizing the cathodes to enhance the cycling stability of lithiumsulfur(Li-S) batteries. However, conventional binders are typically confronted with the drawback of inability for adsorbing lithium polysulfide(Li PS), thus resulting in severe active material losing and rapid capacity fading. Herein, a novel water-soluble hyperbranched poly(amidoamine)(HPAA) binder with controllable hyperbranched molecular structure and abundant amino end groups for Li-S battery is designed and fabricated, which can improve efficient adsorption for Li PS and stability of the sulfur cathodes. Besides, the strong intermolecular hydrogen bonds in HPAA binder can contribute to the structural stability of S cathode and integration of the conductive paths. Therefore, the Li-S battery with this functional binder exhibits excellent cycle performance with a capacity retention of 91% after 200 cycles at 0.1 C.Even at a high sulfur loading of 5.3 mg cm-2, a specific capacity of 601 mA h g-1 can also be achieved.Density functional theory(DFT) calculation further demonstrates that the enhanced electrochemical stability derives from the high binding energy between amino groups and LiP S and the wide electrochemical window(6.87 e V) of HPAA molecule. Based on the above all, this functional polymer will lighten a new species of binders for eco-friendly sulfur cathodes and significantly promote the practical applications of high-performance Li-S batteries. 展开更多
关键词 Functional binder Hyperbranched polymer Sulfur cathode Polysulfide adsorption Lithium-sulfur battery
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自上而下和自下而上相结合提高大规模生态修复规划的实用性和效率——来自社会生态系统的启示 被引量:2
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作者 Zhaowei Ding Hua Zheng +5 位作者 Jun Wang Patrick O’Connor Cong Li xiaodong chen Ruonan Li Zhiyun Ouyang 《Engineering》 SCIE EI CAS CSCD 2023年第12期50-58,共9页
Ecological restoration policies and their implementation are influenced by ecological and socioeconomic drivers.Top-down approach-based spatial planning,emphasizing hierarchical control within government structures,an... Ecological restoration policies and their implementation are influenced by ecological and socioeconomic drivers.Top-down approach-based spatial planning,emphasizing hierarchical control within government structures,and without a comprehensive consideration of social–ecological interactions may result in implementation failure and low efficiency.Although many researchers have indicated the necessity to engage social–ecological interactions between stakeholders in effective planning processes,socioeconomic drivers of ecological restoration on a large scale are difficult to quantify because of data scarcity and knowledge limitations.Here,we established a new ecological restoration planning approach linking a social–ecological system framework to large-scale ecological restoration planning.The new spatial planning approach integrates bottom-up approaches targeting stakeholder interests and provides social considerations for stakeholder behavior analysis.Based on this approach,a meta-analysis is introduced to recognize key socioeconomic and social–ecological factors influencing large-scale ecological restoration implementation,and a stochastic model is constructed to analyze the impact of socioeconomic drivers on the behavior of authorities and participants on a large scale.We used the Yangtze River Basin-based Conversion of Cropland to Forest Program(CCFP),one of the largest payments for ecosystem service programs worldwide,to quantify the socioeconomic impacts of large-scale ecological restoration programs.Current CCFP planning without socioeconomic considerations failed to achieve large-scale program goals and showed low investment efficiency,with 19.71% of the implemented area reconverting to cropland after contract expiry.In contrast,spatial matching between planned and actual restoration increased from 61.55% to 81.86% when socioeconomic drivers were included.In addition,compared to that with the current CCFP implementation,the cost effectiveness of spatial planning with social considerations improved by 46.94%.Thus,spatial optimization planning that integrates both top-down and bottom-up approaches can result in more practical and effective ecological restoration than top-down approaches alone.Our new approach incorporates socioeconomic factors into large-scale ecological restoration planning with high practicality and efficiency. 展开更多
关键词 Social-ecological system Ecological restoration Top-down approach Bottom-up approach
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Design of large-displacement asymmetric piezoelectric microgripper based on flexible mechanisms 被引量:2
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作者 xiaodong chen Siya Hu +2 位作者 Zilong Deng Jinhai Gao Xingjun Gao 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2019年第4期188-193,共6页
The output displacement of the traditional symmetrical microgripper is large,but its micro-components or parts are easily damaged due to the uneven force exerted on the left and right jaws of the gripper.The output fo... The output displacement of the traditional symmetrical microgripper is large,but its micro-components or parts are easily damaged due to the uneven force exerted on the left and right jaws of the gripper.The output force of the traditional asymmetric microgripper is stable.However,its output displacement is small,typically half the output displacement of the symmetric microgripper.To solve these problems,in this study,we designed a large-displacement asymmetric microgripper.First,we calculated the relationship between the theoretical input and output variables based on their geometric relationship.Then,we analyzed the performance of the microgripper using finite element software.Lastly,we used a piezoelectric actuator as the input driver of the microgripper.The errors associated with the theoretical and simulated output displacements were 7.05%and 9.24%,respectively.At 150 V of driving voltage,the maximum output displacement was 224μm,and the actual magnificationwas 11.2 times.Microparts can be gripped in parallel and stably,which confirms the validity of the design. 展开更多
关键词 MICROGRIPPER Asymmetry Piezoelectric drive Experimental verification
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Driving factors and spatio-temporal features underlying industrial SO_(2) emissions in“2+26”in North China and extended cities 被引量:2
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作者 Zhuang Miao Sicen Liu xiaodong chen 《Chinese Journal of Population,Resources and Environment》 2020年第4期296-318,共23页
As one of the largest global emitters of sulfur dioxide(SO_(2)),China faces increasing pressure to achieve sustainable economic and social development.Using panel data of 58 prefecture-level cities in North China betw... As one of the largest global emitters of sulfur dioxide(SO_(2)),China faces increasing pressure to achieve sustainable economic and social development.Using panel data of 58 prefecture-level cities in North China between 2003 and 2017,this paper considers the dynamic spatio-temporal characteristics of industrial SO_(2) emissions in the"2+26"in North China and extended cities in North China and decomposes the determinants of industrial SO_(2) emissions into eight effects using the Generalized Divisia Index Model(GDIM).The contributions of each effect on changes in emissions are assessed on regional,provincial,and prefectural levels,as well as according to various stages.The results indicate the following.First,industrial SO2 emissions in the"2+26"cities in North China and extended cities in North China exhibit spatial autocorrelation and agglomeration effects.Cities with high-high(HH)and low-low(LL)agglomeration patterns were concentrated in Shanxi and Henan provinces,respectively.Second,industrialization,energy consumption,and economic development were the main factors that increased industrial SO2 emissions,while technology,energy sulfur intensity,and economic sulfur intensity were the key factors that reduced them.Third,13 cities,induding Tangshan,were the most important regions where further emissions regulations need to be implemented.These cities were divided into three types and different corresponding measures for reducing their emissions are suggested.Based on the conclusions of this study,this paper puts forward some targeted policy recommendations for reducing industrial SO_(2) emissions according to different categories of cities. 展开更多
关键词 Industrial SO_(2)emissions Temporal and spatial distribution characteristics Generalized divisia index model(GDIM) Factor decomposition
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First experimental comparisons of laser-plasma interactions between spherical and cylindrical hohlraums at SGⅢ laser facility 被引量:2
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作者 Yaohua chen Zhichao Li +33 位作者 Xufei Xie Chunyang Zheng Chuanlei Zhai Liang Hao Dong Yang Wenyi Huo Guoli Ren Jie Liu Xiaoshi Peng Tao Xu Yulong Li Sanwei Li Zhiwen Yang Liang Guo Lifei Hou Yonggang Liu Huiyue Wei Xiangming Liu Weiyi Cha Yukun Li Keli Deng Zheng Yuan Xiayu Zhan Haijun Zhang Baibin Jiang Wei Zhang Kai Du Xuewei Deng Yongkun Ding Xiaofeng Wei Wanguo Zheng xiaodong chen Xiantu He Ke Lan 《Matter and Radiation at Extremes》 SCIE EI CAS 2017年第2期77-86,共10页
We present our recent laser-plasmas instability(LPI)comparison experiment at the SGIII laser facility between the spherical and cylindrical hohlraums.Three kinds of filling are considered:vacuum,gas-filling with or wi... We present our recent laser-plasmas instability(LPI)comparison experiment at the SGIII laser facility between the spherical and cylindrical hohlraums.Three kinds of filling are considered:vacuum,gas-filling with or without a capsule inside.A spherical hohlraum of 3.6 mm in diameter,and a cylindrical hohlraum of 2.4 mm?4.3 mm are used.The capsule diameter is 0.96 mm.A flat-top laser pulse with 3 ns duration and up to 92.73 kJ energy is used.The experiment has shown that the LPI level in the spherical hohlraum is close to that of the outer beam in the cylindrical hohlraum,while much lower than that of the inner beam.The experiment is further simulated by using our 2-dimensional radiation hydrodynamic code LARED-Integration,and the laser back-scattering fraction and the stimulated Raman scatter(SRS)spectrum are post-processed by the high efficiency code of laser interaction with plasmas HLIP.According to the simulation,the plasma waves are strongly damped and the SRS is mainly developed at the plasma conditions of electron density from 0.08 n_(c) to 0.1 n_(c) and electron temperature from 1.5 keV to 2.0 keV inside the hohlraums.However,obvious differences between the simulation and experiment are found,such as that the SRS back-scattering is underestimated,and the numerical SRS spectrum peaks at a larger wavelength and at a later time than the data.These dif-ferences indicate that the development of a 3D radiation hydrodynamic code,with more accurate physics models,is mandatory for spherical hohlraum study. 展开更多
关键词 Laser-plasmas interactions Spherical hohlraum Stimulated Raman scattering Stimulated Brillouin scattering
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Design of a flexible piezoelectric microgripper based on combined amplification principles 被引量:1
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作者 xiaodong chen Zilong Deng +2 位作者 Siya Hu Jinhai Gao Xingjun Gao 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2019年第3期138-143,共6页
Aiming to address the problem of the low amplification ratio of traditional microgrippers,a two-stage microgripper based on the principle of combined amplification was designed with a high amplification ratio and larg... Aiming to address the problem of the low amplification ratio of traditional microgrippers,a two-stage microgripper based on the principle of combined amplification was designed with a high amplification ratio and large displacement,using a simple and compact structure.The relationship between theoretical input variables and output variables were first calculated by a projection theorem.Secondly,the performance of the microgripper was analyzed by finite element analysis(FEA).Finally,the accuracy of the theoretical calculation and FEA was verified experimentally.The results show that the microgripper has high magnification and can be gripped in parallel,with self-adaptability for many irregular shaped micro objects.The actual magnification was 23.2×,which is greater than similar products. 展开更多
关键词 MICROGRIPPER High magnification Projection theorem FEA Experimental verification
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A review of tidal triggering of global earthquakes 被引量:1
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作者 Ruyu Yan xiaodong chen +2 位作者 Heping Sun Jianqiao Xu Jiangcun Zhou 《Geodesy and Geodynamics》 CSCD 2023年第1期35-42,共8页
Earthquake prediction remains a challenging and difficult task for scientists all over the world.The tidal triggering of earthquakes is being proven by an increasing number of investigations,most of which have shown t... Earthquake prediction remains a challenging and difficult task for scientists all over the world.The tidal triggering of earthquakes is being proven by an increasing number of investigations,most of which have shown that earthquakes are positively correlated with tides,and thus,tides provide a potential tool for earthquake prediction,especially for imminent earthquakes.In this study,publications concerning the tidal triggering of earthquakes were compiled and analyzed with regard to global earthquakes,which were classified into three main types:tectonic,volcanic,and slow earthquakes.The results reveal a high correlation between tectonic earthquakes and tides(mainly for semidiurnal and diurnal tides;14-day tides) before and after the occurrence of significant earthquakes.For volcanic earthquakes,observations of volcanoes on the seafloor and land indicate that volcanic earthquakes in near-shore volcanic areas and mid-ocean ridges have a strong correlation with tidal forces,mostly those with semidiurnal and diurnal periods.For slow earthquakes,the periodicity of the tremor duration is highly correlated with semidiurnal and diurnal tides.In conclusion,the tidal triggering of these three types of earthquakes makes a positive contribution to earthquake preparation and understanding the triggering mechanism,and thus,the prediction of these types of earthquakes should be investigated.However,there are still several inadequacies on this topic that need to be resolved to gain a definitiveanswer regarding the tidal triggering of all earthquakes.The main inadequacies are discussed in this paper from our point of view. 展开更多
关键词 Tidal triggering Tectonic earthquakes Volcanic earthquakes Slow earthquakes Earthquake prediction
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A Wideband E-Plane Crossover Coupler for Terahertz Applications 被引量:1
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作者 Xiaohe cheng Zhiyan Liu +2 位作者 Yuan Yao Junsheng Yu xiaodong chen 《China Communications》 SCIE CSCD 2021年第5期245-254,共10页
In this paper,a new approach to design terahertz(THz)E-plane crossover coupler is reported.By cascading two symmetrical septum polarizers,a simple structure with wide operating bandwidth and high isolation performance... In this paper,a new approach to design terahertz(THz)E-plane crossover coupler is reported.By cascading two symmetrical septum polarizers,a simple structure with wide operating bandwidth and high isolation performance is achieved.The working principle is explained by operating waveguide modes.To simplify the optimization process,the scattering matrix(S-matrix)of the crossover is calculated.Two prototypes loaded and unloaded electromagnetic band gap(EBG)are fabricated and measured.The electrical contact problem at assembly plane is eliminated by the prototype loaded EBG.A measured bandwidth of 17.3%from 92.5 to 110 GHz for reflection and isolation coefficients<-15 dB and transmission coefficient>-2 dB is achieved. 展开更多
关键词 butler matrix crossover coupler high isolation MULTI-BEAM THZ
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Recent Progress on Hydrogeodesy in China 被引量:1
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作者 Wei FENG Yuhao XIONG +7 位作者 Shuang YI Bo ZHONG xiaodong chen Yulong ZHONG Yuanjin PAN Lin LIU Wei WANG Min ZHONG 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第3期124-134,共11页
Modern geodetic technologies,including high-precision ground-based gravity measurements,satellite gravimetry,satellite altimetry,Global Navigation Satellite Systems(GNSS),and Interferometric Synthetic Aperture Radar(I... Modern geodetic technologies,including high-precision ground-based gravity measurements,satellite gravimetry,satellite altimetry,Global Navigation Satellite Systems(GNSS),and Interferometric Synthetic Aperture Radar(InSAR),offer a wealth of observations for monitoring global hydrological processes with exceptional accuracy and spatio-temporal resolutions.Mass redistribution and Earth’s surface deformation over land related to global and regional water cycling can be inferred from modern gravimetry,altimetry,GNSS,and InSAR techniques.Hydrogeodesy becomes an emerging field of geodesy aiming to analyze the changes of water in the Earth system.The paper introduces the China’s advances in hydrogeodesy in recent years.It brings together multiple geodetic teams’work from China,showcasing the application of modern geodetic technologies in the field of hydrology,including research on terrestrial water storage,groundwater storage,glaciers/ice sheets,and reservoir water storage. 展开更多
关键词 geodetic measurement hydrogeodesy HYDROLOGY satellite gravity GNSS ALTIMETRY
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How can the Dual-atom Catalyst FeCo-NC Surpass Singleatom Catalysts Fe-NC/Co-NC in CO_(2) RR?-CO Intermediate Assisted Promotion via a Synergistic Effect 被引量:1
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作者 Shoufu Cao Sainan Zhou +7 位作者 Hongyu chen Shuxian Wei Siyuan Liu Xiaojing Lin xiaodong chen Zhaojie Wang Wenyue Guo Xiaoqing Lu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第1期300-308,共9页
Atomically dispersed catalysts are widely adopted in CO_(2)reduction reaction(CO_(2)RR)due to maximal atomic utilization and high catalytic activity.Dual-atom catalysts(DACs),with more dispersed active sites and disti... Atomically dispersed catalysts are widely adopted in CO_(2)reduction reaction(CO_(2)RR)due to maximal atomic utilization and high catalytic activity.Dual-atom catalysts(DACs),with more dispersed active sites and distinct electronic structures compared with single-atom catalysts(SACs),may exhibit diverse catalytic performance.Herein,the DAC FeCo-NC and SAC Fe-NC/Co-NC are employed as probes to explore DACs advantage in CO_(2)RR.Results show that the moderate interaction between the dual-atom center and N coordination balances structural stability and catalytic activity.CO is the only product on Fe-NC/Co-NC,and the high limiting potentials from−1.22 to−1.67 V inhibit further reduction.FeCo-NC assisted with CO intermediate exhibits low limiting potentials of−0.64 V for both CH_(3)OH and CH 4,comparable to those on Cu-based catalysts.Under circumstance of applied potentials,CO_(2)RR on FeCo-NC has greater advantages in yielding CH_(3)OH and CH 4 than that on Fe-NC/Co-NC,and hydrogen evolution reaction is severely inhibited.The intrinsic essence is that dual-atom center can provide large spin-polarization and multi-electron transfer capability,rendering CO intermediates as effective electronic and geometric modifiers in CO_(2)RR.This work highlights FeCo-NC as a high-performance CO_(2)RR catalyst toward deep-reduction C1 products and elucidates CO intermediate assisted promotion mechanism via a dual-atom synergistic effect. 展开更多
关键词 dispersed LIMITING RENDERING
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Assessment of atrial electromechanical interval using echocardiography after catheter ablation in patients with persistent atrial fibrillation 被引量:2
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作者 xiaodong chen Minglong chen +4 位作者 Yingying Wang Bing Yang Weizhu Ju Fengxiang Zhang Kejiang Cao 《The Journal of Biomedical Research》 CAS CSCD 2016年第6期483-489,共7页
We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler(PW) and pulse tissue Doppler imaging(PW-... We sought to investigate variation of atrial electromechanical interval after catheter ablation procedure in patients with persistent atrial fibrillation using pulse Doppler(PW) and pulse tissue Doppler imaging(PW-TDI).A total of 25 consecutive in-patients with persistent atrial fibrillation,who restored sinus rhythm after ablation procedure,were recruited in our cardiac center.Echocardiography was performed on each patient at 2 hours,1 day,5 days,1 month and 3 months after the ablation therapy,and atrial electromechanical delay was measured simultaneously by PW and PW-TDI.There was no significant difference between PW and TDI in measuring atrial electromechanical delay.However,at postoperative 2 hours,peak A detection rates were mathematically but nonsignificantly greater by PWTDI than by PW.Second,there was a significant decreasing trend in atrial electromechanical interval from postoperative 2 hours to 3 months,but only postoperative 2-hour atrial electromechanical interval was significantly greater than atrial electromechanical interval at other time.Lastly,patients without postoperative 2-hour atrial electromechanical interval had a significantly longer duration of atrial fibrillation as compared to those with postoperative 2-hour atrial electromechanical interval,by the PW or by PW-TDI,respectively.In patients with persistent atrial fibrillation,atrial electromechanical interval may decrease significantly within the first 24 hours after ablation but remain consistent later,and was significantly related to patients' duration of atrial fibrillation.Atrial electromechanical interval,as a potential predicted factor,is recommended to be measured by either PW or TDI after24 hours,when patients had recovered sinus rhythm by radiofrequency ablation. 展开更多
关键词 atrial fibrillation echocardiography tissue Doppler imaging atrial electromechanical interval
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