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78篇 您的检索式:作者名="Guoyi Zhang"
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1Rates of litter decomposition in terrestrial ecosystems:global patterns and controlling factors显示文摘Aims We aim to construct a comprehensive global database of litter decomposition rate(k value)estimated by surface floor litterbags,and investigate the direct and indirect effects of impact factors such as geographic factors(latitude and altitude),climatic factors(mean annual tempePlrature,MAT;mean annual precipitation,MAP)and litter quality factors(the contents of N,P,K,Ca,Mg and C:N ratio,lignin:N ratio)on litter decomposition.Methods We compiled a large data set of litter decomposition rates(k values)from 110 research sites and conducted simple,multiple regression and path analyses to explore the relationship between the k values and impact factors at the global scale.Important findings The k values tended to decrease with latitude(LAT)and lignin content(LIGN)of litter but increased with temperature,precipitation and nutrient concentrations at the large spatial scale.Single factor such as climate,litter quality and geographic variable could not explain litter decomposition rates well.However,the combination of total nutrient(TN)elements and C:N accounted for 70.2%of the variation in the litter decomposition rates.The combination of LAT,MAT,C:N and TN accounted for 87.54%of the variation in the litter decomposition rates.These results indicate that litter quality is the most important direct regulator of litter decomposition at the global scale.This data synthesis revealed significant relationships between litter decomposition rates and the combination of climatic factor(MAT)and litter quality(C:N,TN).The global-scale empirical relationships developed here are useful for a better understanding and modeling of the effects of litter quality and climatic factors on litter decomposition rates.Deqiang Zhang Dafeng Hui Yiqi Luo Guoyi Zhou 2008Journal of Plant Ecology2008,1,2:99
2Karyotype Stability and Unbiased Fractionation in the Paleo-Allotetraploid Cucurbita Genomes显示文摘Honghe Sun Shan WU Guoyu Zhang Chen Jiao Shaogui Guo Yi Ren Jie Zhang Haiying Zhang Guoyi Gong Zhangcai Jia Fan Zhang Jiaxing Tian William J. Lucas Jeff J. Doyle Haizhen Li Zhangjun Fei Yong Xu 2017Molecular Plant2017,10,10:33
3Altered trends in carbon uptake in China’s terrestrial ecosystems under the enhanced summer monsoon and warming hiatus显示文摘The carbon budgets in terrestrial ecosystems in China are strongly coupled with climate changes.Over the past decade,China has experienced dramatic climate changes characterized by enhanced summer monsoon and decelerated warming.However,the changes in the trends of terrestrial net ecosystem production(NEP)in China under climate changes are not well documented.Here,we used three ecosystem models to simulate the spatiotemporal variations in China's NEP during 1982–2010 and quantify the contribution of the strengthened summer monsoon and warming hiatus to the NEP variations in four distinct climatic regions of the country.Our results revealed a decadal-scale shift in NEP from a downtrend of–5.95 Tg C/yr^2(reduced sink)during 1982–2000 to an uptrend of 14.22 Tg C/yr^2(enhanced sink)during 2000–10.This shift was essentially induced by the strengthened summer monsoon,which stimulated carbon uptake,and the warming hiatus,which lessened the decrease in the NEP trend.Compared to the contribution of 56.3%by the climate effect,atmospheric CO2 concentration and nitrogen deposition had relatively small contributions(8.6 and 11.3%,respectively)to the shift.In conclusion,within the context of the global-warming hiatus,the strengthening of the summer monsoon is a critical climate factor that enhances carbon uptake in China due to the asymmetric response of photosynthesis and respiration.Our study not only revealed the shift in ecosystem carbon sequestration in China in recent decades,but also provides some insight for understanding ecosystem carbon dynamics in other monsoonal areas.Honglin He Shaoqiang Wang Li Zhang Junbang Wang Xiaoli Ren Lei Zhou Shilong Piao Hao Yan Weimin Ju Fengxue Gu Shiyong Yu Yuanhe Yang Miaomiao Wang Zhongen Niu Rcmg Ge Huimin Yan Mei Huang Guoyi Zhou Yongfei Bai Zongqiang Xie Zhiyao Tang Bingfang Wu Leiming Zhang Nianpeng He Qiufeng Wang Guirui Yu 2019National Science Review2019,6,3:24
4Climate and litter C/N ratio constrain soil organic carbon accumulation显示文摘Soil organic carbon(SOC) plays critical roles in stabilizing atmospheric CO2 concentration, but the mechanistic controls on the amount and distribution of SOC on global scales are not well understood. In turn, this has hampered the ability to model global C budgets and to find measures to mitigate climate change. Here, based on the data from a large field survey campaign with 2600 plots across China’s forest ecosystems and a global collection of published data from forested land, we find that a low litter carbon-to-nitrogen ratio(C/N) and high wetness index(P/PET, precipitation-to-potentialevapotranspiration ratio) are the two factors that promote SOC accumulation, with only minor contributions of litter quantity and soil texture. The field survey data demonstrated that high plant diversity decreased litter C/N and thus indirectly promoted SOC accumulation by increasing the litter quality. We conclude that any changes in plant-community composition, plant-species richness and environmental factors that can reduce the litter C/N ratio, or climatic changes that increase wetness index, may promote SOC accumulation. The study provides a guideline for modeling the carbon cycle of various ecosystem scales and formulates the principle for land-based actions for mitigating the rising atmospheric CO2 concentration.Guoyi Zhou Shan Xu Philippe Ciais Stefano Manzoni Jingyun Fang Guirui Yu Xuli Tang Ping Zhou Wantong Wang Junhua Yan Gengxu Wang Keping Ma Shenggong Li Sheng Du Shijie Han Youxin Ma Deqiang Zhang Juxiu Liu Shizhong Liu Guowei Chu Qianmei Zhang Yuelin Li Wenjuan Huang Hai Ren Xiankai Lu Xiuzhi Chen 2019National Science Review2019,6,4:21
5Effect of N and P addition on soil organic C potential mineralization in forest soils in South China显示文摘Atmospheric nitrogen deposition is at a high level in some forests of South China. The effects of addition of exogenous N and P on soil organic carbon mineralization were studied to address: (1) if the atmospheric N deposition promotes soil C storage through decreasing mineralization; (2) if the soil available P is a limitation to organic carbon mineralization. Soils (0-10 cm) was sampled from monsoon evergreen broad-leaved forest (MEBF), coniferous and broad-leaved mixed forest (CBMF), and Pinus massoniana forest (PMF) in Dinghushan Biosphere Reserve (located in Guangdong Province, China). The soils were incubated at 25°C for 45 weeks, with addition of N (NH4NO3 solution) or P (KH2PO4 solution). CO2-C emission and the inorganic N (NH4+-N and NO3?-N) of the soils were determined during the incubation. The results showed that CO2-C emission decreased with the N addition. The addition of P led to a short-term sharp increase in CO2 emission after P application, and the responses of CO2-C evolution to P addition in the later period of incubation related to forest types. Strong P inhibition to CO2 emission occurred in both PMF and CBMF soils in the later incubation. The two-pool kinetic model was fitted well to the data for C turnover in this experiment. The model analysis demonstrated that the addition of N and P changed the distribution of soil organic C between the labile and recalcitrant pool, as well as their mineralization rates. In our experiment, soil pH can not completely explain the negative effect of N addition on CO2-C emission. The changes of soil inorganic N during incubation seemed to support the hypothesis that the polymerization of added nitrogen with soil organic compound by abiotic reactions during incubation made the added nitrogen retard the soil organic carbon mineralization. We conclude that atmospheric N deposition contributes to soil C accretion in the three subtropical forest ecosystems, however, the shortage of soil available P in CBMF and PMF may also retard soil organic C mineralization.OUYANG, Xuejun ZHOU, Guoyi HUANG, Zhongliang ZHOU, Cunyu LI, Jiong SHI, Junhui ZHANG, Deqiang 2008Journal of Environmental Sciences2008,20,9:17
6Discrimination of abiogenic and biogenic alkane gases显示文摘We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and CH4/3He values of abiogenic and biogenic (referring to the thermogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2) Abiogenic alkane gases have a carbon isotopic reversal trend (δ 13C1> δ 13C2> δ 13C3> δ 13C4) with δ 13C1>-30‰ in general; 3) Gases with R/Ra >0.5 and δ 13C11 δ 13C2>0 are of abiogenic origin; 4) Gases (meth- ane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.DAI JinXing ZOU CaiNeng ZHANG ShuiChang LI Jian NI YunYan HU GuoYi LUO Xia TAO ShiZhen ZHU GuangYou MI JingKui LI ZhiSheng HU AnPing YANG Chun ZHOU QingHua SHUAI YanHua ZHANG Ying MA ChengHua 2008Science China Earth Sciences2008,51,12:17
7Molecular geochemical characteristics of gas source rocks from the Upper Triassic Xujiahe Formation indicate transgression events in the Sichuan Basin显示文摘The geochemical characteristics of saturated and aromatic hydrocarbons from different formations and lithologies provide ob-vious evidence for transgressions that occurred during Upper Triassic Xujiahe stage in Sichuan Basin with a great impact on the source input and depositional environment.A clear dual peak distribution for normal alkanes and obvious abundant com-pounds sourced from bacteria and algae in whole oil gas chromatogram indicates the abundance of lower organisms input.The ratio of Pr/Ph is low,ranging from 0.33 to 0.86 with an average of 0.60,quite different from Pr/Ph >2.0 for coal measures in swamp environment,representing source rocks from saline lake or marine facies.In the gas source rocks extracts,abundant β-carotane,-carotane,and their degradated series were detected in the whole oil chromatogram,indicating a reducing envi-ronment.The concentrations of methyl steranes and dinosteranes are high.The content of polycyclic aromatic sulfur heterocy-cles(PASH) is relatively higher in aromatic fraction and the assemblage of fluorene,dibenzofuran,and dibenzothiophene is different from the typical saline lake and the regular swamp facies source rocks,manifesting the transgression effects on gas source rocks.ZHANG Min HUANG GuangHui LI HongBo HU GuoYi ZHANG ShuiChang 2012Science China Earth Sciences2012,55,8:10
8Overexpression of the Watermelon Ethylene Response Factor ClERF069 in Transgenic Tomato Resulted in Delayed Fruit Ripening显示文摘Watermelon fruit undergoes distinct development stages with dramatic changes during fruit ripening.To date,the molecular mechanics of watermelon ripening remain unclear.Genetic and transcriptome evidences suggested that the ethylene response factor(ERF)gene ClERF069 may be an important candidate factor affecting watermelon fruit ripening.To dissect the roles of ClERF069 in fruit ripening,structure and phylogenetic analysis were performed using the amplified full-length sequence.Normal-ripening watermelon 97103,non-ripening watermelon PI296341-FR and the RIL population were used to analyze ClERF069 expression dynamics and the correlation with fruit ripening indexs.The results indicated that ClERF069 belongs to ERF family group VI and show high homology(83%identity)to melon ERF069-like protein.ClERF069 expression in watermelon flesh was negatively correlated with fruit lycopene content and sugar content during fruit ripening progress.Further transgenic evidences indicated that overexpression of 35S:ClERF069 in tomato noticeably delayed the ripening process up to 5.2 days.Lycopene,β-carotenoid accumulation patterns were altered and ethylene production patterns in transgenic fruits was significantly delayed during fruit ripening.Taken together,watermelon ethylene response factor ClERF069 was concluded to be a negative regulator of fruit ripening.Ming Zhou Shaogui Guo Shouwei Tian Jie Zhang Yi Ren Guoyi Gong Changbao Li Haiying Zhang Yong Xu 2020Horticultural Plant Journal2020,6,4:9
9Effect and quantitative evaluation of CO_2 derived from organic matter in coal on the formation of tight sandstone reservoirs显示文摘Tight reservoirs are widely distributed, especially in coal measure strata. Identification of the densification mechanism of the tight sandstone reservoirs is critical in effectively exploring and exploiting tight gas/oil resources. In this study, the gas formation from type Ⅲ organic matter in coal was kinetically modeled for the whole diagenetic stage, from the shallow buried biogas generation stage to the deep buried thermal gas generation stage. The results demonstrated that during hydrocarbon formation, quantities of non-hydrocarbon gases, such as CO2 , were generated. The proportion of CO2 is about 50%-70% of that of the C1-5 , which far exceeds the CO2 content (0-5%) in the natural gas in the sedimentary basins. Geological case study analysis showed that a considerable part of the 'lost' gaseous CO2 was converted into carbonate cement under favorable environments. Under the ideal conditions, the volume of the carbonate cement transformed from total CO 2 generated by 1 m 3 coal (Junggar Basin Jurassic, TOC 67%) can amount to 0.32 m 3 . Obviously, this process plays a very important role in the formation of tight sandstone reservoirs in the coal measures. Our results also show that the kinetic generation processes of C1-5 and CO2 are asynchronous. There are two main stages of CO2 generation, one at the weak diagenetic stage and the other at the over-mature stage, which are different from large-scale multi-stage hydrocarbon gas generation. Therefore, we can understand the mechanism of tight gas charging by determining the filling time for a tight gas reservoir and the key period of CO2 generation. Further analysis and correlation studies of a specific region are of great significance for determining the mechanism and modeling gas charging in tight reservoirs. It should be noted that the formation of tight sandstone reservoirs is the combined result of complex organic-inorganic and water-rock-hydrocarbon interactions. The details of spatial and temporal distributions of the carbonate cement derived from the organic CO2 , which combines with metal ions (Ca/Mg/Fe) in the formation water, should be further investigated.SHUAI YanHua ZHANG ShuiChang GAO Yang LU Hong CHEN JianPing MI JingKui LIU JinZhong HU GuoYi 2013Science China Earth Sciences2013,56,5:7
10Modulation of Sex Expression in Four Forms of Watermelon by Gibberellin, Ethephone and Silver Nitrate显示文摘There has been no systematic research on the effect of plant growth regulators and silver nitrate treatments on the control of sex expression in watermelon. In this study, we tested sex expression responses of four watermelon forms(monoecism, gynoecism, andromonoecism,and hermaphrodite) to gibberellin, ethephon and silver nitrate treatments. Results have shown that, in monoecious plants, gibberellins(GA_3)and ethephon treatments reduced the percentage of female flowers and delayed the occurrence of the first female flower, while silver nitrate induced the formation of bisexual flowers. In gynoecious plants, both ethephon and silver nitrate treatments transformed some female flowers into bisexual flowers, and treatment with ethephon resulted in a mass of abnormal flowers, while no obvious effect of treatment with GA_3 was observed. In andromonoecious plants, ethephon and GA_3 treatments delayed the occurrence of the first bisexual flower, and GA_3 reduced the percentage of bisexual flowers, while no distinct effect for silver nitrate treatment was observed. In hermaphroditic plants, ethephon treatment induced the appearance of numerous abnormal flowers, while no obvious effects for GA_3 and silver nitrate treatments were observed.We analyzed the transcription levels of all the expressed aminocyclopropane-1-carboxylic acid synthase(ACS) homologues in two gynoecious mutants and their wild types. We also tested the gene expression of CitACS4 which had been recognized as the andromonoecious gene in all treatments. All these results suggested that the best masculinizing treatment for breeding of the gynoecious line is silver nitrate, which repressed the expression of CitACS4 and induced many bisexual flowers for use in self-fertilization subsequently.ZHANG Jie SHI Jianting JI Gaojie ZHANG Haiying GONG Guoyi GUO Shaogui REN Yi FAN Jianguang TIAN Shouwei XU Yong 2017Horticultural Plant Journal2017,3,3:6
11CO_2 efflux from different forest soils and impact factors in Dinghu Mountain, China显示文摘CO2 fluxes from soils and related environmental factors were measured in three forest ecosystems of Dinghu Mountain using static chamber-gas chromatograph technique for one year. The seasonal pattern of CO2 flux, contribution of litter on total CO2 flux and the correlations of CO2 flux with soil temperature and soil water content were examined for each type of forest. The results were given as followings: (1) The seasonal patterns of CO2 flux from soil of the three types of forest were similar, with a higher CO2 flux in rainy season than in dry season. The comparative relations of mean annual CO2 fluxes between the three sites were expressed as:monsoon forest > mixed forest > pine forest. (2) CO2 fluxes from litter decomposition in monsoon forest, mixed forest and pine forest accounted for 24.43%, 41.75% and 29.23% of the corresponding total CO2 fluxes from forest floor, respectively. (3) Significant relationships were found between CO2 fluxes and soil temperatures at 5 cm depth for the three types of forest, which could be best described by exponential equations. The calculated Q10 values based on soil temperature at 5 cm depth ranged from 1.86 to 3.24. More significant relationships were found between CO2 fluxes and soil water content when the annual variation coefficients of soil moisture were higher.ZHOU Cunyu, ZHOU Guoyi, ZHANG Deqiang, WANG Yinghong & LIU Shizhong Dinghushan Forest Ecosystem Research Station, Chinese Academy of Sciences, Guangzhou 510650, China Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China 2005Science China Earth Sciences2005,48,z1:6
12Relationship between plant canopy characteristics and photosynthetic productivity in diverse cultivars of cotton(Gossypium hirsutum L.)显示文摘Genotype and plant type affect photosynthetic production by changing the canopy structure in crops.To analyze the mechanism of action of heterosis and plant type on canopy structure in cotton(Gossypium hirsutum L.),we had selected two cotton hybrids(Shiza 2,Xinluzao 43) and two conventional varieties(Xinluzao 13,Xinluzao 33) with different plant types in this experiment.We studied canopy characteristics and their correlation with photosynthesis in populations of different genotypes and plant types during yield formation in Xinjiang,China.Canopy characteristics including leaf area index(LAI),mean foliage tilt angle(MTA),canopy openness(DIFN),and chlorophyll relative content(SPAD).The results showed that LAI and SPAD peak values were higher and their peak values arrived later,and the adjustment capacity of MTA during the flowering and boll-forming stages was stronger in Xinluzao 43,with the normal-leaf,pagoda plant type,than these values in other varieties.DIFN of Xinluzao 43 remained between0.09 and 0.12 during the flowering and boll-forming stages,but was lower than that in the other varieties during the boll-opening stage.Thus,these characteristics of Xinluzao 43 were helpful for optimizing the light environment and maximizing light interception,thereby increasing photosynthetic capability.The photosynthetic rate and photosynthetic area were thus affected by cotton genotype as changes in the adjustment range of MTA,increases in peak values of LAI and SPAD,and extension of the functional stage of leaves.Available photosynthetic area and canopy light environment were affected by cotton plant type as changes in MTA and DIFN.Heterosis expression and plant type development were coordinated during different growth stages,the key to optimizing the canopy structure and further increasing yield.Guoyi Feng Honghai Luo Yali Zhang Ling Gou Yandi Yao Yongzeng Lin Wangfeng Zhang 2016The Crop Journal2016,4,6:6
13GaN-based substrates and optoelectronic materials and devices显示文摘In order to solve the problems of GaN heteroepitaxy on sapphire substrate,some techniques were explored.Freestanding GaN substrates have been made by hydride vapor phase epitaxy(HVPE),laser lift-off(LLO),and chemical mechanical polishing techniques.Wafer bending and cracking in the HVPE growth were partly settled by pulsed flow modulation method.High-crystal quality was established for 1.2 mm thick GaN substrate by X-ray diffraction measurement,in which the full width of half maximum values were 72,110 arcsec for(102),(002)peaks.A novel micro-size patterned sapphire substrate(PSS)and a nano PSS were also fabricated.High-power vertical structure light emitting diodes(VSLEDs)have been developed by Au–Sn eutectic wafer bonding,homemade micro-area LLO,and light extraction structure preparation.The high-injection-level active region with low temperature GaN sandwiched layers was used for lowefficiency droop.The light output power of VSLED was achieved as 400 mW driven at 350 mA,and the dominant wavelength is about 460 nm.The structures and properties of strain modulated superlattices(SLs)and quantum wells as well as advanced simulation of carriers transport across the electron blocking layer were investigated in laser diodes.The hole concentration was achieved as high as1.6 9 1018cm-3in AlGaN/GaN SLs:Mg by inserting an AlN layer.High-quality AlGaN epilayers and structures were grown by MOCVD.Some device structures of UV LEDs and detectors were demonstrated.The emission wavelength of 262 nm UV LED has been successfully fabricated.At last,high-quality InN and InGaN materials for solar cell were grown by boundary-temperature-controlled epitaxy and growth-temperature-controlled epitaxy.Hall-effect measurement showed a recorded electron mobility of 3,280 cm2/(V s)and a residual electron concentration of 1.47 9 1017cm-3at 300 K.Guoyi Zhang Bo Shen Zhizhong Chen Xiaodong Hu Zhixin Qin Xinqiang Wang Jiejun Wu Tongjun Yu Xiangning Kang Xingxing Fu Wei Yang Zhijian Yang Zhizhao Gan 2014Chinese Science Bulletin2014,59,12:4
14Effects of precipitation on soil organic carbon fractions in three subtropical forests in southern China显示文摘Aims The aim of this study was to investigate the effects of precipitation changes on soil organic carbon(SOC)fractions in subtropical forests where the precipitation pattern has been altered for decades.Methods We conducted field manipulations of precipitation,including ambient precipitation as a control(CK),double precipitation(DP)and no precipitation(NP),for 3 years in three forests with different stand ages(broadleaf forest[BF],mixed forest[MF]and pine forest[PF])in subtropical China.At the end of the experiment,soil samples were collected to assay SOC content,readily oxidizable organic carbon(ROC)and non-readily oxidizable organic carbon(NROC),as well as soil microbial biomass carbon(MBC),pH and total nitrogen content.Samples from the forest floors were also collected to analyze carbon(C)functional groups(i.e.alkyl C,aromatic C,O-alkyl C and carbonyl C).Furthermore,fine root biomass was measured periodically throughout the experiment.Important Findings Among the forests,ROC content did not exhibit any notable differences,while NROC content increased significantly with the stand age.This finding implied that the SOC accumulation observed in these forests resulted from the accumulation of NROC in the soil,a mechanism for SOC accumulation in the mature forests of southern China.Moreover,NP treatment led to significant reductions in both ROC and NROC content and therefore reduced the total SOC content in all of the studied forests.Such decreases may be due to the lower plant-derived C inputs(C quantity)and to the changes in SOC components(C quality)indicated by C functional groups analyses under NP treatment.DP treatment in all the forests also tended to decrease the SOC content,although the decreases were not statistically significant with the exception of SOC and ROC content in PF.This finding indicated that soils in MF and in BF may be more resistant to precipitation increases,possibly due to less water limitations under natural conditions in the two forests.Our results therefore highlight the different responses of SOC and its fractions to precipitation changes among the forests and suggest that further studies are needed to improve our understanding of SOC dynamics in such an important C sink region.Xiaomei Chen Deqiang Zhang Guohua Liang Qingyan Qiu Juxiu Liu Guoyi Zhou Shizhong Liu Guowei Chu Junhua Yan 2016Journal of Plant Ecology2016,9,1:4
15Reduced turnover rate of topsoil organic carbon in old-growth forests:a case study in subtropical China显示文摘Background:Old-growth forests are irreplaceable with respect to climate change mitigation and have considerable carbon(C)sink potential in soils.However,the relationship between the soil organic carbon(SOC)turnover rate and forest development is poorly understood,which hinders our ability to assess the C sequestration capacity of soil in old-growth forests.Methods:In this study,we evaluated the SOC turnover rate by calculating the isotopic enrichment factor β(defined as the slope of the regression between ^(13)C natural abundance and log-transformed C concentrations)along 0-30 cm soil profiles in three successional forests in subtropical China.A lower β(steeper slope)is associated with a higher turnover rate.The three forests were a 60-year-old P.massoniana forest(PF),a 100-year-old coniferous and broadleaved mixed forest(MF),and a 400-year-old monsoon evergreen broadleaved forest(BF).We also analyzed the soil physicochemical properties in these forests to examine the dynamics of SOC turnover during forest succession and the main regulators.Results:The β value for the upper 30-cm soils in the BF was significantly(p<0.05)higher than that in the PF,in addition to the SOC stock,although there were nonsignificant differences between the BF and MF.The β value was significantly(p<0.05)positively correlated with the soil recalcitrance index,total nitrogen,and available nitrogen contents but was significantly(p<0.01)negatively correlated with soil pH.Conclusions:Our results demonstrate that SOC has lower turnover rates in old-growth forests,accompanied by higher soil chemical recalcitrance,nitrogen status,and lower soil pH.This finding helps to elucidate the mechanism underlying C sequestration in old-growth forest soils,and emphasizes the important value of old-growth forests among global C sinks.Xin Xiong Juxiu Liu Guoyi Zhou Qi Deng Huiling Zhang Guowei Chu Ze Meng Deqiang Zhang 2021Forest Ecosystems2021,8,4:4
16Changes in leaf nutrient traits and photosynthesis of four tree species: effects of elevated [CO_(2)], N fertilization and canopy positions显示文摘Aims Leaf traits of trees exposed to elevated[CO_(2)]in association with other environmental factors are poorly understood in tropical and subtropical regions.Our goal was to investigate the impacts of elevated[CO_(2)]and N fertilization on leaf traits in southern China.Methods Four tree species,Schima superba Gardn.et Champ.(S.superba),Ormosia pinnata(Lour.)Merr(O.pinnata),Castanopsis hystrix AC.DC.(C.hystrix)and Acmena acuminatissima(Blume)Merr.et Perry(A.acuminatissima)were studied in a factorial combination of atmospheric[CO_(2)](ambient at~390μmol mol^(-1)and elevated[CO_(2)]at~700μmol mol^(-1))and N fertilization(ambient and ambient+100 kg N ha^(-1)year^(-1))in open-top chambers in southern China for 5 years.Leaf mass per unit leaf area(LMA),leaf nutrient concentration and photosynthesis(A_(sat))were measured.Important Findings Results indicated that leaf traits and photosynthesis were affected differently by elevated[CO_(2)]and N fertilization among species.Elevated[CO_(2)]decreased LMA in all species,while N fertilization did not affect LMA.Leaf mass-based N concentration(N_(M))was significantly greater in O.pinnata and C.hystrix grown in elevated[CO_(2)]but was lower in S.superba.Leaf mass-based P concentration(P_(M))was significantly greater in C.hystrix and A.acuminatissima exposed to elevated[CO_(2)]but was lower in S.superba.N fertilization significantly increased P_(M) in O.pinnata but decreased P_(M) in S.superba.Photosynthetic stimulation in O.pinnata,C.hystrix and A.acuminatissima was sustained after 5 years of CO_(2)fumigation.N fertilization did not modify the effects of elevated[CO_(2)]on photosynthesis.Leaf traits(N_(M),N_(A),P_(M),P_(A))and light-saturated photosynthesis were decreased from the upper to lower canopy.Canopy position did not alter the responses of leaf traits and photosynthesis to elevated[CO_(2)].Results suggest that photosynthetic stimulation by elevated[CO_(2)]in native species in subtropical regions may be sustained in the long term.Juxiu Liu Deqiang Zhang Guoyi Zhou Honglang Duan 2012Journal of Plant Ecology2012,5,4:4
17Determination of the local magnitudes of small earthquakes using a dense seismic array in the Changning-Zhaotong Shale Gas Field,Southern Sichuan Basin显示文摘With the development of unconventional shale gas in the southern Sichuan Basin,seismicity in the region has increased significantly in recent years.Though the existing sparse regional seismic stations can capture most earthquakes with ML≥2.5,a great number of smaller earthquakes are often omitted due to limited detection capacity.With the advent of portable seismic nodes,many dense arrays for monitoring seismicity in the unconventional oil and gas fields have been deployed,and the magnitudes of those earthquakes are key to understand the local fault reactivation and seismic potentials.However,the current national standard for determining the local magnitudes was not specifically designed for monitoring stations in close proximity,utilizing a calibration function with a minimal resolution of 5 km in the epicentral distance.That is,the current national standard tends to overestimate the local magnitudes for stations within short epicentral distances,and can result in discrepancies for dense arrays.In this study,we propose a new local magnitude formula which corrects the overestimated magnitudes for shorter distances,yielding accurate event magnitudes for small earthquakes in the Changning-Zhaotong shale gas field in the southern Sichuan Basin,monitored by dense seismic arrays in close proximity.The formula is used to determine the local magnitudes of 7,500 events monitored by a two-phased dense array with several hundred 5 Hz 3 C nodes deployed from the end of February 2019 to early May 2019 in the Changning-Zhaotong shale gas field.The magnitude of completeness(MC)using the dense array is-0.1,compared to MC 1.1 by the sparser Chinese Seismic Network(CSN).In addition,using a machine learning detection and picking procedure,we successfully identify and process some 14,000 earthquakes from the continuous waveforms,a ten-fold increase over the catalog recorded by CSN for the same period,and the MC is further reduced to-0.3 from-0.1 compared to the catalog obtained via manual processing using the same dense array.The proposed local magnitude formula can be adopted for calculating accurate local magnitudes of future earthquakes using dense arrays in the shale gas fields of the Sichuan Basin.This will help to better characterize the local seismic risks and potentials.Wen Yang GuoYi Chen LingYuan Meng Yang Zang HaiJiang Zhang JunLun Li 2021Earth and Planetary Physics2021,5,6:4
18Geochemical characteristics and origin of light hydrocarbons in biogenic gas显示文摘The light hydrocarbon geochemical characteristics of biogenic gases from Sebei 1 gas field in the Qaidam Basin, Baoshan gas field in the Baoshan Basin and Alaxin gas field, Puqian gas pool, Aonan gas pool in the Songliao Basin are studied and the origin is discussed based on the composition and isotope data of gases. The isoalkane contents among light hydrocarbons in natural gas show a negative relationship with δ13C1 values. The isoalkane contents of the gases with δ13C1 values of less than ?60‰ are also high with more than 40% among light hydrocarbons in Sebei 1 gas field and Puqian gas pool. Moreover, the 2,2-dimethylbutane and 2-methylpentane, mainly sourced from bacteria, have predominance among isoalkanes, which suggests that light hydrocarbons in biogenic gases from these gas fields or pools were probably generated by microbial action. However, the cycloalkane contents among light hydrocarbons in biogenic gas are related to δ13C1 values positively. In Alaxin gas field and Aonan gas pool, where δ13C1 values of biogenic gases are less than ?60‰, the average contents of cycloalkane are higher than 44%. Light hydrocarbons among biogenic gases from these gas fields were probably generated by catalysis. The isoalkane and cycloalkane contents among light hydrocarbons from biogenic gases in the Baoshan gas field are both high, which might be generated by these two actions. The results show that the data of light hydrocarbons in biogenic gas can provide important information for understanding the generation mechanisms of light hydrocarbons during geological evolution and identifying biogenic gas and low mature gas.HU GuoYi LUO Xia LI ZhiSheng ZHANG Ying YANG Chun LI Jin NI YunYan TAO XiaoWan 2010Science China Earth Sciences2010,53,6:3
19Comprehensive Proteomic Profiling of Patients'Tears Identifies Potential Biomarkers for the Traumatic Vegetative State显示文摘The vegetative state is a complex condition with unclear mechanisms and limited diagnostic, prognostic,and therapeutic methods. In this study, we aimed to explore the proteomic profile of tears from patients in a traumatic vegetative state and identify potential diagnostic markers using tears—a body fluid that can be collected noninvasively. Using i TRAQ quantitative proteomic technology, in the discovery phase, tear samples collected from 16 patients in a traumatic vegetative state and 16 normal individuals were analyzed. Among 1080 identified tear proteins, 57 were upregulated and 15 were downregulated in the patients compared to the controls. Bioinformatics analysis revealed that the differentially-expressed proteins were mainly involved in the wound response and immune response signaling pathways. Furthermore, we verified the levels of 7 differentially-expressed proteins in tears from50 traumatic vegetative state patients and 50 normal controls(including the samples used in the discovery phase) using ELISA. The results showed that this 7-protein panel had a high discrimination ability for traumatic vegetative state(area under the curve = 0.999). In summary, the altered tear proteomic profile identified in this study provides a basis for potential tear protein markers for diagnosis and prognosis of the traumatic vegetative state and also provides novel insights into the mechanisms of traumatic vegetative state.Qilin Tang Chao Zhang Xiang Wu Wenbin Duan Weiji Weng Junfeng Feng Qing Mao Shubin Chen Jiyao Jiang Guoyi Gao 2018Neuroscience Bulletin2018,34,4:3
20Modification of polarization filtering technique in HF ground wave radar显示文摘The polarization filter using three orthogonal linear polarization antennas can suppress more disturbances than the polarization filter using two orthogonal linear polarization antennas in HF ground wave radar. But the algorithm of the threedimension filter is relatively complicated and not suitable for real-time processing. It can’t use linear and nonlinear polarization vector translation technique directly. A modified polarization filter which is simple and has same suppressing ability as the three-dimension polarization filter is given. It only has half parameters of the primary one. Some problems about estimation of polarization parameters and selection of disturbances are discussed. A method of holding the phase of radar backscatter signal constantly is put forward so that unstationary disturbance signal can be processed.Zhang Guoyi Tan Zhongji Wang Jiantao 2006Journal of Systems Engineering and Electronics2006,17,4:3
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