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127篇 您的检索式:作者名="Chunmei Chen"
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1Identifying paleoflood deposits archived in Zhongba Site,the Three Gorges reservoir region of the YangtzeRiver,China显示文摘Based on the principle that the present is the key to the past , detailed analyses, such as AMS 14C dating, grain size, component and morphology of heavy minerals, micro-morphology of zircon, Rb/Sr, magnetic susceptibility and total organic carbon (TOC), were conducted to identify paleoflood sediments archived in Zhongba Site. The results indicate that the plaeoflood sediments bear great similarities with modern flood sediments in the following aspects: (1) probability cumulative curves mainly show a pattern of 3―4 segments; (2) grain-size distribution of suspended matter ranges between 3 and 10Ф; (3) the sediments are well-sorted, most of which are suspended matter (>50%); (4) the same species, quantity and morphology of heavy minerals; (5) scanning electronic microscope images show that shapes of zircon are mainly oval and nearly spheral, rounded due to long-distance transport; (6) higher Rb/Sr values (0.55―0.66)than those of sediments from cultural layers (0.03―0.26); (7) magnetic susceptibility values (133.73―433.05 10-6m3/kg) are lower than those of sediments from cultural layers (959.25―2442.44 10?6 m3/kg); (8) TOC (0.14%―0.33%) are lower than those of sediments from cultural lay-ers (1.13%―2.95%). Our results demonstrate that, except for the 1981 flood, there are at least six paleoflood events that occurred during the Qing Dynasty, the middle of Song Dy-nasty, the early Warring States (400BC―350BC), the West Zhou Dynasty (920BC―900BC), the Xia Dynasty (2070BC―1600BC), and the late Neolithic Age (3000BC―2300BC), respectively .ZHU Chen ZHENG Chaogui MA Chunmei SUN Zhibin ZHU Guangyao WANG Huilin GAO Huazhong WANG Pengling HUANG Run 2005Chinese Science Bulletin2005,50,21:28
2Using iron fertilizer to control Cd accumulation in rice plants: A new promising technology显示文摘Effects of two kinds of iron fertilizer, FeSO4 and EDTA·Na2Fe were studied on cadmium accumulation in rice plants with two rice genotypes, Zhongzao 22 and Zhongjiazao 02, with soil culture systems. The results showed that application of iron fertilizers could hardly make adverse effects on plant growth and rice grain yield. Soil application of EDTA·Na2Fe significantly reduced the Cd accumulation in rice roots, shoots and rice grain. Cd concentration in white rice of both rice genotypes in the treatment of soil application of EDTA·Na2Fe was much lower than 0.2 mg/kg, the maximal Cd permission concentra- tion in cereal crop foods in State standard. However, soil application of FeSO4 or foliar application of FeSO4 or EDTA·Na2Fe resulted in the significant increase of Cd accumulation in rice plants including rice grain compared with the control. The results also showed iron fertilizers increased the concentra- tion of iron, copper and manganese element in rice grain and also affected zinc concentration in plants. It may be a new promising way to regulate Cd accumulation in rice grain in rice production through soil application of EDTA·Na2Fe fertilizers to maintain higher content of available iron and ferrous iron in soils.SHAO GuoSheng, CHEN MingXue, WANG DanYing, XU ChunMei, MOU RenXiang, CAO ZhaoYun & ZHANG XiuFu China National Rice Research Institute, Hangzhou 31006, China 2008Science China(Life Sciences)2008,51,3:28
3Emission factors of gaseous carbonaceous species from residential combustion of coal and crop residue briquettes显示文摘Experiments were performed to measure the emission factors (EFs) of gaseous carbonaceous species, such as CO2, CO, CH4, and non-methane volatile organic compounds (NMVOCs), from the combustion of five types of coal of varying organic maturity and two types of biomass briquettes under residential burning conditions. Samples were collected in stainless steel canisters and 2,4- dinitrophenylhydrazine (DNPH) cartridges and were analyzed by GC FID/MS and HPLC, respectively. The EFs from crop residue briquette burning were generally higher than those from coals, with the exception of CO2. The dominant NMVOC species identified in coal smoke were carbonyls (41.7%), followed by C2 unsaturated hydrocarbons (29.1%) and aromatics (12.1%), while C2 unsaturated hydrocarbons were the dominant species (68.9%) emitted from the combustion of crop residue briquettes, followed by aromatics (14.4%). A comparison of burning normal crop residues in stoves and the open field indicated that briquettes emitted a larger proportion of ethene and acetylene. Both combustion efficiency and coal organic maturity had a significant impact on NMVOC EFs from burning coal: NMVOC emissions increased with increasing coal organic maturity but decreased as the combustion efficiency improved. Emissions from the combustion of crop residue briquettes from stoves occurred mainly during the smoldering process, with low combustion efficiency. Therefore, an improved stove design to allow higher combustion efficiency would be beneficial for reducing emissions of carbonaceous air pollutants.Qin WANG Chunmei GENG Sihua LU Wentai CHEN Min SHAO 2013Frontiers of Environmental Science & Engineering2013,7,1:17
4Characteristics of paleoflood deposits archived in unit T0403 of Yuxi Site in the Three Gorges reservoir areas,China显示文摘Based on the detailed analyses,multi-proxies such as AMS 14 C dating,grain size,component and morphology of heavy minerals,micromorphology of zircon,magnetic susceptibility,Rb/Sr and Hg content are used to research the paleoflood sediments archived in the Yuxi Site.The research indicates that, since 7.6 kaBP,at least 16 times of paleoflood with water level above Wusong Elevation 147.024 m(a.s.l.) left deposits in the Neolithic layers of unit T0403 from the Yuxi Site.The results are induced from the following aspects:(1)The plaeoflood sediments take on great similarities with modern flood sediments in the Yuxi Site and Zhongba Site in probability cumulative curves which mainly show a pattern of 3 segments in fluvial pattern.(2)There is some resemblance between the heavy mineral components and the zircon shape characteristics of paleoflood deposits and those of modern flood deposits.(3) Magnetic susceptibility values(40.44―70.10SI)are lower than those of sediments from cultural layers (59.59―188.68SI).(4)Hg values(290.71―742.51 ng/g)are lower than those of sediments from cultural layers(344.16―10518.17 ng/g).(5)Rb/Sr values are higher than those of sediments from cultural layers, while those of the 4th,5th,6th,7th,8th cultural layers are high,which shows that they are inundated by paleoflood.The reason for many flood deposits existing is related to the site situated on the first terrace where the Yuxi River joins with the Yangtze River.As there are some similarities between the plaeoflood sediments and those of the Zhongba Site,it is feasible to confirm the existence of paleoflood sediments based on the above points.ZHU Cheng MA ChunMei XU WeiFeng BAI JiuJiang ZHENG ChaoGui ZHU GuangYao WANG HuiLin CHEN Ye LU XueFeng 2008Chinese Science Bulletin2008,53,S1:16
5Spore-pollen-climate factor transfer function and paleoenvironment reconstruction in Dajiuhu,Shennongjia,Central China显示文摘The identified results of 121 surface sediment spore-pollen samples in Shennongjia and meteorological data base of 30 years(January,1971―December,2000)of 7 meteorological stations around Dajiuhu, Shennongjia are used in this study.Selecting 55 species of common spore-pollen with the method of space fitting and stepwise regression we construct the pollen climate factor transfer function of annual mean tem- perature:T=7.649-2.33097X Abies -0.10873X Betula -0.17352X Compositae -0.13176X Cruciferae +0.13356XEuphorbiaceae -0.83069X Campanulaceae +1.96494XPyrrosia+0.38411XPteris+2.77741XSelaginella+0.04439XMonolites.We had reconstructed annual mean temperature series by use of the sporo-pollen samples concentra-tion percentage in peat section with 297 cm thickness in Dajiuhu since 15.753 kaBP.The temperature series reflect well the character of climatic change since the late glacial,which indicates extreme cold climate event of the Oldest Dryas,the Older Dryas,the Younger Dryas and the 8.2 kaBP,the same to the climate fluctuations of Bolling Warm Period and Allerod Warm Period,and the character of temperature change fluctuating frequently at the transition age from the late glacial to the Holocene.The reconstructed temperature also indicate Holocene Optimum,late Holocene warm-dry climate,and the character of climatic change in Dajiuhu in the last 1 ka.The conclusion is that the sporo-pollen samples have important climatic significance to surface sediment and the section of Dajiuhu,Shennongjia and important reference value to studying climatic change during the last glaciation by the temperature transfer function and reconstructed temperature series.ZHU Cheng CHEN Xing ZHANG GuangSheng MA ChunMei ZHU Qing LI ZhongXuan XU WeiFeng 2008Chinese Science Bulletin2008,53,S1:15
6Effect of various crop rotations on rice yield and nitrogen use efficiency in paddy–upland systems in southeastern China显示文摘To evaluate the effects of various rotation systems on rice grain yield and N use efficiency, a paddy–upland cropping experiment(2013–2016) was conducted in southeastern China. The experiment was designed using six different rice––winter crop rotations: rice–fallow(RF),rice–wheat(RW), rice–potato with rice straw mulch(RP), rice–green manure(Chinese milk vetch; RC–G), rice–oilseed rape(RO), and rice–green manure crop(oilseed rape with fresh straw incorporated into soil at flowering; RO–G) and three N rates, N0(0 kg N ha-1), N1(142.5 kg N ha-1), and N2(202.5 kg N ha-1). Average rice yields in the RF(5.93 t ha-1) rotation were significantly lower than those in the rotations with winter crops(7.20–7.48 t ha-1)under the N0 treatment, suggesting that incorporation of straw might be more effective for increasing soil N than winter fallow. The rice yield differences among the rotations varied by year with the N input. In general, the grain yields in the RP and RO–G rotations –were respectively 11.6–28.5% and 14.80–37.19% higher than those in the RF in plots with N applied. Increasing the N rate may have tended to minimize the average yield gap between the RF and the other rotations; the yield gaps were 18.55%, 4.14%, and 0.23% in N0, N1, and N2, respectively. However, the N recovery efficiency in the RF was significantly lower than that in other rotations, except for 2015 under both N1 and N2 rates, a finding that implies a large amount of chemical N loss. No significant differences in nitrogen agronomic efficiency(NAE) and physiological efficiency(NPE) were found between the rotations with legume(RC–G) and non–legume(RO and RW) winter crops, a result that may be due partly to straw incorporation. For this reason, we concluded that the return of straw could reduce differences in N use efficiency between rotations with and without legume crops. The degree of synchrony between the crop N demand and the N supply was evaluated by comparison of nitrogen balance degree(NBD) values. The NBD values in the RP and RW were significantly lower than those in the other rotations under both N1 and N2 rates. Thus,in view of the higher grain yield in the RP compared to the RW under the N1 rate, the RP rotation might be a promising practice with comparable grain yield and greater N use efficiency under reduced N input relative to the other rotations. The primary yield components of the RF and RP were identified as number of panicles m-2 and numbers of kernels panicle-1, respectively. The NAE and NPE were positively correlated with harvest index, possibly providing a useful indicator for evaluating N use efficiency.Song Chen Shaowen Liu Xi Zheng Min Yin Guang Chu Chunmei Xu Jinxiang Yan Liping Chen Danying Wang Xiufu Zhang 2018The Crop Journal2018,6,6:13
7Signal overcomplete representation and sparse decomposition based on redundant dictionaries显示文摘Decomposing a signal based upon redundan dictionaries is a new method for data representation on sig- nal processing. It approximates a signal with an overcom- plete system instead of an orthonormal basis to provide a sufficient choice for adaptive sparse decompositions. Re- placing the original data with a sparse approximation can result in not only a higher compression ratio, but also greater flexibility in capturing the inherent structure of the natura signals with the redundancy of dictionaries. This paper gives an overview of a series of recent results in this field, and deals with the relationship between sparsity of signal de- composition and incoherence of dictionaries with BP and MP algorithms. The current and future challenges of the dic- tionary construction are discussed.ZHANG Chunmei YIN Zhongke CHEN Xiangdong XIAO Mingxia 2005Chinese Science Bulletin2005,50,23:13
8A seed-specific AP2-domain transcription factor from soybean plays a certain role in regulation of seed ger-mination显示文摘Plant seed development and germination are under strict temporal and spatial regulation, and tran-scription factors play important roles in this regulation. In the present study we identified an EST ex-pressed specifically in the developing soybean seeds. The full length of the gene was obtained through further RACE analysis and the gene was named GmSGR. Sequence analysis revealed that this gene belonged to the AP2/ERF transcription factor family. Its AP2 domain had the highest similarity with that of the A-3 member AtABI4 of DREB subgroup in the AP2/ERF family in Arabidopsis. GmSGR did not exhibit transcriptional activation activity in the yeast assay system. GmSGR was overexpressed in Arabidopsis and the germination rates of the transgenic seeds were significantly higher than that of the wild type seeds under higher concentrations of ABA and glucose respectively. However, the germina-tion rates of the transgenic seeds were lower than that of control under salt stress. The expression of AtEm6 and AtRD29B was higher in the seedlings of the transgenic plants than that in the wild-type seedlings. These results suggest that GmSGR may confer reduced ABA sensitivity and enhanced salt sensitivity to the transgenic seeds through regulating the expression of AtEm6 and AtRD29B genes.WANG ChunMei, WANG HuiWen, ZHANG JinSong & CHEN ShouYi National Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Bei-jing 100101, China 2008Science China(Life Sciences)2008,51,4:11
9Intermetallic phase formation and evolution during homogenization and solution in Al-Zn-Mg-Cu alloys显示文摘The effects of major alloy element contents of Zn,Mg,Cu in Al-Zn-Mg-Cu alloys on the formation and evolution of intermetallic phases during casting,homogenization and solution treatment have been investigated through using X-ray diffraction,scanning electron microscopy and differential scanning calorimetry.Experimental results showed that a relatively higher Zn content with lower Mg and Cu contents was beneficial to the formation of MgZn2phase instead of the Al2CuMg phase,which resulted in the unicity of the intermetallics in the Al matrix,and that the MgZn2phase was easier for diffusion and dissolution during homogenization and solution than the Al2CuMg phase.Additionally,the results of the first-principles calculations gave support for explaining the experimental phenomena.A larger absolute value of formation enthalpy and a smaller value of binding energy of the MgZn2phase,as compared with the Al2CuMg phase,give it priority to precipitate during casting and make it easier to re-dissolve during homogenization and solution treatment.What’s more,higher elastic constants with severe anisotropy of Young’s modulus make undissolved blocks of Al2CuMg phase act as crack initiation,which degrade the performance of the materials.LI ChunMei CHEN ZhiQian ZENG SuMin CHENG NanPu CHEN TianXiao 2013Science China(Technological Sciences)2013,56,11:10
10Curcumin protects against ischemic spinal cord injury The pathway effect显示文摘Inducible nitric oxide synthase and N-methyl-D-aspartate receptors have been shown to participate in nerve cell injury during spinal cord ischemia.This study observed a protective effect of curcumin on ischemic spinal cord injury.Models of spinal cord ischemia were established by ligating the lumbar artery from the left renal artery to the bifurcation of the abdominal aorta.At 24 hours after model establishment,the rats were intraperitoneally injected with curcumin.Reverse transcription-polymerase chain reaction and immunohistochemical results demonstrated that after spinal cord ischemia,inducible nitric oxide synthase and N-methyl-D-aspartate receptor mRNA and protein expression significantly increased.However,curcumin significantly decreased inducible nitric oxide synthase and N-methyl-D-aspartate receptor mRNA and protein expression in the ischemic spinal cord.Tarlov scale results showed that curcumin significantly improved motor function of the rat hind limb after spinal cord ischemia.The results demonstrate that curcumin exerts a neuroprotective effect against ischemic spinal cord injury by decreasing inducible nitric oxide synthase and N-methyl-D-aspartate receptor expression.Jinhua Zhang Hao Wei Meimei Lin Chunmei Chen Chunhua Wang Maobai Liu 2013Neural Regeneration Research2013,8,36:9
11Ectopic expression of soybean GmKNT1 in Arabidopsis results in altered leaf morphology and flower identity显示文摘Plant morphology is specified by leaves and flowers, and the shoot apical meristem (SAM) defines the architecture of plant leaves and flowers. Here, we reported the characterization of a soybean KNOX gene GmKNT1, which was highly homologous to Arabidopsis STM. The GmKNT1 was strongly expressed in roots, flowers and developing seeds. Its expression could be induced by IAA, ABA and JA, but inhibited by GA or cytokinin. Staining of the transgenic plants overexpressing GmKNT1-GUS fusion protein revealed that the GmKNT1 was mainly expressed at lobe region, SAM of young leaves, sepal and carpel, not in seed and mature leaves. Scanning electron micros-copy (SEM) disclosed multiple changes in morphology of the epidermal cells and stigma. The transgenic Arabidopsis plants overexpress-ing the GmKNT1 showed small and lobed leaves, shortened internodes and small clustered inflorescence. The lobed leaves might result from the function of the meristems located at the boundary of the leaf. Compared with wild type plants, transgenic plants had higher ex-pression of the SAM-related genes including the CUP, WUS, CUC1, KNAT2 and KNAT6. These results indicated that the GmKNT1 could affect multiple aspects of plant growth and development by regulation of downstream genes expression.Jun Liu Da Ha Zongming Xie Chunmei Wang Huiwen Wang Wanke Zhang Jinsong Zhang Shouyi Chen 2008Journal of Genetics and Genomics2008,35,7:8
12Agronomic performance of drought-resistance rice cultivars grown under alternate wetting and drying irrigation management in southeast China显示文摘Compared to drought-susceptible rice cultivars(DSRs),drought-resistance rice cultivars(DRRs)could drastically reduce the amount of irrigation water input and simultaneously result in higher grain yield under water-saving irrigation conditions.However,the mechanisms underlying these properties are unclear.We investigated how improved agronomic traits contribute to higher yield and higher water use efficiency(WUE)in DRRs than in DSRs under alternate wetting and drying(AWD).Two DRRs and two DSRs were field-grown in 2015 and 2016 using two different irrigation regimes:continuous flooding(CF)and AWD.Under CF,no statistical differences in grain yield and WUE were observed between DRRs and DSRs.Irrigation water under the AWD regime was 275–349 mm,an amount 49.8%–56.2% of that(552–620 mm)applied under the CF regime.Compared to CF,AWD significantly decreased grain yield in both DRRs and DSRs,with a more significant reduction in DSRs,and WUE was increased in DRRs,but not in DSRs,by 9.9%–23.0% under AWD.Under AWD,DRRs showed a 20.2%–26.2% increase in grain yield and an 18.6%–24.5% increase in WUE compared to DSRs.Compared to DSRs,DRRs showed less redundant vegetative growth,greater sink capacity,higher grain filling efficiency,larger root biomass,and deeper root distribution under AWD.We conclude that these improved agronomic traits exert positive influences on WUE in DRRs under AWD.Guang Chu Tingting Chen Song Chen Chunmei Xu Danying Wang Xiufu Zhang 2018The Crop Journal2018,6,5:8
13Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China显示文摘Domestic coal stove is widely used in China, especially for countryside during heating period of winter, and polycyclic aromatic hydrocarbons(PAHs) are important in flue gas of the stove. By using dilution tunnel system, samples of both gaseous and particulate phases from domestic coal combustion were collected and 18 PAH species were analyzed by GC-MS. The average emission factors of total 18 PAH species was 171.73 mg/kg, ranging from 140.75 to 229.11 mg/kg for bituminous coals, while was 93.98 mg/kg, ranging from 58.48 to 129.47 mg/kg for anthracite coals. PAHs in gaseous phases occupied 95% of the total of PAHs emission of coal combustion. In particulate phase, 3-ring and 4-ring PAHs were the main components, accounting for 80% of the total particulate PAHs. The total toxicity potency evaluated by benzo[a]pyrene-equivalent carcinogenic power, sum of 7 carcinogenic PAH components and 2,3,7,8-tetrachlorodibenzodioxin had a similar tendency. And as a result, the toxic potential of bituminous coal was higher than that of anthracite coal. Efcient emission control should be conducted to reduce PAH emissions in order to protect ecosystem and human health.Chunmei Geng Jianhua Chen Xiaoyang Yang Lihong Ren Baohui Yin Xiaoyu Liu Zhipeng Bai 2014Journal of Environmental Sciences2014,26,1:8
14Application of neural networks for permanent magnet synchronous motor direct torque control显示文摘Neural networks require a lot of training to understand the model of a plant or a process. Issues such as learning speed, stability, and weight convergence remain as areas of research and comparison of many training algorithms. The application of neural networks to control interior permanent magnet synchronous motor using direct torque control (DTC) is discussed. A neural network is used to emulate the state selector of the DTC. The neural networks used are the back-propagation and radial basis function. To reduce the training patterns and increase the execution speed of the training process, the inputs of switching table are converted to digital signals, i.e., one bit represent the flux error, one bit the torque error, and three bits the region of stator flux. Computer simulations of the motor and neural-network system using the two approaches are presented and compared. Discussions about the back-propagation and radial basis function as the most promising training techniques are presented, giving its advantages and disadvantages. The system using back-propagation and radial basis function networks controller has quick parallel speed and high torque response.Zhang Chunmei Liu Heping Chen Shujin Wang Fangjun 2008Journal of Systems Engineering and Electronics2008,19,3:6
15Rhizosphere Aeration Improves Nitrogen Transformation in Soil, and Nitrogen Absorption and Accumulation in Rice Plants显示文摘Two rice cultivars(Xiushui 09 and Chunyou 84)were used to evaluate the effects of various soil oxygen(O2)conditions on soil nitrogen(N)transformation,absorption and accumulation in rice plants.The treatments were continuous flooding(CF),continuous flooding and aeration(CFA),and alternate wetting and drying(AWD).The results showed that the AWD and CFA treatments improved soil N transformation,rice growth,and N absorption and accumulation.Soil NO3–content,nitrification activity and ammonia-oxidising bacteria abundance,leaf area,nitrate reductase activity,and N absorption and accumulation in rice all increased in both cultivars.However,soil microbial biomass carbon and pH did not significantly change during the whole period of rice growth.Correlation analysis revealed a significant positive correlation between the nitrification activity and ammonia-oxidising bacteria abundance,and both of them significantly increased as the total N accumulation in rice increased.Our results indicated that improved soil O2 conditions led to changing soil N cycling and contributed to increases in N absorption and accumulation by rice in paddy fields.XU Chunmei CHEN Liping CHEN Song CHU Guang WANG Danying ZHANG Xiufu 2020Rice science2020,27,2:6
16Motion Error Compensation of Multi-legged Walking Robots显示文摘Existing errors in the structure and kinematic parameters of multi-legged walking robots,the motion trajectory of robot will diverge from the ideal sports requirements in movement.Since the existing error compensation is usually used for control compensation of manipulator arm,the error compensation of multi-legged robots has seldom been explored.In order to reduce the kinematic error of robots,a motion error compensation method based on the feedforward for multi-legged mobile robots is proposed to improve motion precision of a mobile robot.The locus error of a robot body is measured,when robot moves along a given track.Error of driven joint variables is obtained by error calculation model in terms of the locus error of robot body.Error value is used to compensate driven joint variables and modify control model of robot,which can drive the robots following control model modified.The model of the relation between robot's locus errors and kinematic variables errors is set up to achieve the kinematic error compensation.On the basis of the inverse kinematics of a multi-legged walking robot,the relation between error of the motion trajectory and driven joint variables of robots is discussed.Moreover,the equation set is obtained,which expresses relation among error of driven joint variables,structure parameters and error of robot's locus.Take MiniQuad as an example,when the robot MiniQuad moves following beeline tread,motion error compensation is studied.The actual locus errors of the robot body are measured before and after compensation in the test.According to the test,variations of the actual coordinate value of the robot centroid in x-direction and z-direction are reduced more than one time.The kinematic errors of robot body are reduced effectively by the use of the motion error compensation method based on the feedforward.WANG Liangwen CHEN Xuedong WANG Xinjie TANG Weigang SUN Yi PAN Chunmei 2012Chinese Journal of Mechanical Engineering2012,25,4:6
17Smog chamber study on the evolution of fume from residential coal combustion显示文摘Domestic coal stoves are widely used in countryside and greenbelt residents in China for heating and cooking,and emit considerable pollutants to the atmosphere because of no treatment of their exhaust,which can result in deteriorating local air quality.In this study,a dynamic smog chamber was used to investigate the real-time emissions of gaseous and particulate pollutants during the combustion process and a static smog chamber was used to investigate the fume evolution under simulate light irradiation.The real-time emissions revealed that the total hydrocarbon (THC) and CO increased sharply after ignition,and then quickly decreased,indicating volatilization of hydrocarbons with low molecular weight and incomplete combustion at the beginning stage of combustion made great contribution to these pollutants.There was evident shoulder peak around 10min combustion for both THC and CO,revealing the emissions from vitrinite combustion.Additionally,another broad emission peak of CO after 30min was also observed,which was ascribed to the incomplete combustion of the inertinite.Compared with THC and CO,there was only one emission peak for NOx,SO 2 and particular matters at the beginning stage of combustion.The fume evolution with static chamber simulation indicated that evident consumption of SO 2 and NOx as well as new particle formation were observed.The consumption rates for SO 2 and NOx were about 3.44% hr-1 and 3.68% hr-1,the new particle formation of nuclei particles grew at a rate of 16.03 nm/hr during the first reaction hour,and the increase of the diameter of accumulation mode particles was evident.The addition of isoprene to the diluted mixture of the fume could promote O 3 and secondary particle formation.Chunmei Geng Kun Wang Wei Wang Jianhua Chen Xiaoyu Liu Hongjie Liu 2012Journal of Environmental Sciences2012,24,1:5
18A novel selective autophagy receptor,CCDC50,delivers K63 polyubiquitination-activated RIG-I/MDA5 for degradation during viral infection显示文摘Autophagy is a con served process that delivers cytosolic substa nces to the lysosome for degradatio n,but its direct role in the regulation of antiviral inn ate immu nity remains poorly un derstood.Here,through high-throughput screeni ng,we discovered that CCDC50 functions as a previously unknown autophagy receptor that negatively regulates the type I interferon(IFN)signaling pathway initiated by RIG-I-like receptors(RLRs),the sensors for RNA viruses.The expression of CCDC50 is enhanced by viral infection,and CCDC50 specifically recognizes K63-polyubiquitinated RLRs,thus delivering the activated RIG-I/MDA5 for autophagic degradation.The associatio n of CCDC50 with phagophore membrane protei n LC3 is con firmed by crystal structure analysis.In contrast to other known autophagic cargo receptors that associate with either the LIR-docking site(LDS)or the UIMdocking site(UDS)of LC3,CCDC50 can bind to both LDS and UDS,representing a new type of cargo receptor.In mouse models with RNA virus infection,CCDC50 deficiency reduces the autophagic degradation of RIG-I/MDA5 and promotes type I IFN responses,resulting in enhaneed viral resistance and improved survival rates.These results reveal a new link between autophagy and antiviral innate immune resp on ses and provide additional in sights into the regulatory mecha nisms of RLR-mediated antiviral signaling.Panpan Hou Kongxiang Yang Penghui Jia Lan Liu Yuxin Lin Zibo Li Jun Li Shuliang Chen Shuting Guo Ji'An Pan Junyu Wu Hong Peng Weijie Zeng Chunmei Li Yingfang Liu Deyin Guo 2021Cell Research2021,31,1:5
19Pollen-based Holocene quantitative temperature reconstruction on the eastern Tibetan Plateau using a comprehensive method framework显示文摘Quantitative climate reconstruction on long timescales can provide important insights for understanding the climate variability and providing valuable data for simulations. Unfortunately, the credibility of some attempts was hampered by incomplete reconstruction procedures. We here establish a comprehensive framework resting on high-quality Chinese modern pollen database, including modern pollen data screening, calibration set selection, major climate factor analysis, appropriate model selection, strict statistical assessment of results and ecological interpretation. The application of this framework to three high-resolution pollen records from the eastern Tibetan Plateau allows accurate quantitative inferences of Holocene temperature changes, which is the major control of regional vegetation. The results show that the mean warmest month temperature(MTwa)during the early Holocene was ca. 10.4℃ and reached the highest value at 8.5–6 ka BP(ca. 11℃). The early and mid-Holocene(11–5 ka BP) warmth was followed by 1.2℃ temperature decrease, culminating in the coolest temperatures of the Holocene during the Neoglacial cooling. Superimposing on the general cooling trend, MTwareveals a significant 500-yr periodicity with varying intensities through time, showing that warm(cold) intervals are in phase with solar maxima(minima) periods. This spectral similarity indicates a possible connection of multi-century scale climate fluctuations with solar forcing.Chen LIANG Yan ZHAO Feng QIN Zhuo ZHENG Xiayun XIAO Chunmei MA Huan LI Wenwei ZHAO 2020Science China Earth Sciences2020,63,8:5
20Characteristics of particulate-bound polycyclic aromatic hydrocarbons emitted from industrial grade biomass boilers显示文摘Polycyclic aromatic hydrocarbons(PAHs) are carcinogenic or mutagenic and are important toxic pollutants in the flue gas of boilers. Two industrial grade biomass boilers were selected to investigate the characteristics of particulate-bound PAHs: one biomass boiler retro-fitted from an oil boiler(BB1) and one specially designed(BB2) biomass boiler. One coal-fired boiler was also selected for comparison. By using a dilution tunnel system, particulate samples from boilers were collected and 10 PAH species were analyzed by gas chromatography–mass spectrometry(GC–MS). The total emission factors(EFs) of PAHs ranged from 0.0064 to0.0380 mg/kg, with an average of 0.0225 mg/kg, for the biomass boiler emission samples. The total PAH EFs for the tested coal-fired boiler were 1.8 times lower than the average value of the biomass boilers. The PAH diagnostic ratios for wood pellets and straw pellets were similar.The ratio of indeno(1,2,3-cd)pyrene/[indeno(1,2,3-cd)pyrene + benzo(g,h,i)perylene] for the two biomass boilers was lower than those of the reference data for other burning devices, which can probably be used as an indicator to distinguish the emission of biomass boilers from that of industrial coal-fired boilers and residential stoves. The toxic potential of the emission from wood pellet burning was higher than that from straw pellet burning, however both of them were much lower than residential stove exhausts.Xiaoyang Yang Chunmei Geng Xuesong Sun Wen Yang Xinhua Wang Jianhua Chen 2016Journal of Environmental Sciences2016,28,2:4
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