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Effect of joint structure and slope direction on the development of collapsing gully in tuffaceous sandstone area in south china

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International Soil and Water Conservation Research 2020年第2期8卷 131-140页

作者： Yusong Deng Xiaoqian Duan Shuwen Ding Chongfa Cai Forestry College of Guangxi University NanningGuangxi530004China College of Resources and Environment of Huazhong agricultural University WuhanHubei430070China

This study focuses on the collapsing gullies in tuffaceous sandstone area and investigates the slope di-rection and morphological characteristics of the main and branch gullies. Furthermore, we assess the structural characteristics of the rock joints within this area, including their strike, dip direction and dip angle. The results show that there are 405 collapsing gullies in the study area. The slope directions associated with collapsing gullies and the directions of the main gullies largely fall within the ranges of NE20°-NE90°, SE90°-SE160°, SW240°-SW270°, and NW270°-NW290°. The collapsing gullies include 1103 branch gullies in total, most of which have directions that fall within the ranges of NE20°-NE40°, NE50°-NE70°, NW280°-NW300°, and NW330°-NW350°. The joints in the bedrock are directional and regional, and they can be divided into two main groups. The number of southward dip directions is greater than the number of northward dip directions, and most of the measured dip angles are greater than 60°. The mean dip angle is greatest for joints with measured strike values of NW280°-NW290°, with a value of 85.2°. The development of collapse gullies is affected by both the slope direction and joints. The slope direction determines the direction of the main gullies, with a correlation coefficient of 0.809 (P<0.01). The branch gullies are mainly affected by joints, with a correlation coefficient of 0.876 (P<0.01). The joint structure also influences the degree of development of the collapsing gullies, and the average depth of the gullies that parallel the dominant joint orientation is significantly larger than that of gullies with other directions. Moreover, the average depth of the gullies associated with the dip angle of 85.2° measured relative to the joint strike is 6.89 m, which is significantly greater than that associated with lower dip angles. The dip angles of joints have an important effect on the infiltration of water, and high dip angles accelerate the er

关键词： Soil erosion Joint Slope direction Main gully Branch gully

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Improving grain yield, nitrogen use efficiency and radiation use efficiency by dense planting, with delayed and reduced nitrogen application, in double cropping rice in south china

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Journal of Integrative Agriculture 2021年第2期20卷 565-580页

作者： FU You-qiang ZHONG Xu-hua ZENG Jia-huan LIANG Kai-ming PAN Jun-feng XIN Ying-feng LIU Yan-zhuo HU Xiang-yu PENG Bi-lin CHEN Rong-bing HU Rui HUANG Nong-rong Rice Research Institute Guangdong Academy of Agricultural Sciences/Guangdong Key Laboratory of New Technology for Rice BreedingGuangzhou 510640P.R.China Guiping agricultural Technology Extension Station Guiping 537200P.R.China

Improving both grain yield and resource use efficiencies simultaneously is a major challenge in rice ***,few studies have focused on integrating dense planting with delayed and reduced nitrogen application to enhance grain yield,nitrogen use efficiency (NUE) and radiation use efficiency (RUE) in rice (Oryza sativa L.) in the double rice cropping system in south china.A high-yielding indica hybrid rice cultivar (Yliangyou 143) was grown in field experiments in Guangxi,south china,with three cultivation managements:farmers’practice (FP),dense planting with equal N input and delayed N application (DPEN) and dense planting with reduced N input and delayed N application (DPRN).The grain yields of DPRN reached 10.6 and 9.78 t ha^(–1) in the early and late cropping seasons,respectively,which were significantly higher than the corresponding yields of FP by 23.9–29.9%.The grain yields in DPEN and DPRN were *** in DPRN reached 65.2–72.9 kg kg^(–1),which was 61.2–74.1% higher than that in FP and 24.6–30.2% higher than that in *** in DPRN achieved 1.60–1.80 g MJ^(–1),which was 28.6–37.9% higher than that in *** productive tiller percentage in DPRN was 7.9–36.2% higher than that in *** in crop growth rate,leaf area duration,N uptake from panicle initiation to heading and enhancement of the apparent transformation ratio of dry weight from stems and leaf sheaths to panicles all contributed to higher grain yield and higher resource use efficiencies in *** analysis revealed that the agronomic and physiological traits mentioned above were significantly and positively correlated with grain *** trials carried out in Guangdong in 2018 and 2019 also showed that DPRN performed better than *** conclude that DPRN is a feasible approach for simultaneously increasing grain yield,NUE and RUE in the double rice cropping system in south china.

关键词： grain yield resource use efficiencies indica rice planting density nitrogen application strategy

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Size selectivity of combined square and diamond mesh codends of shrimp beam trawl for banded scad Caranx(Atule)kalla in the northern south china Sea

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Journal of Oceanology and Limnology 2018年第5期36卷 1880-1890页

作者： YANG Bingzhong YANG Lin TAN Yongguang YAN Lei ZHANG Peng LI Jie south china Sea Fisheries Research Institute Chinese Academy of Fishery Science Key Lab of south china Sea Fishery Resources Exploitation ＆ Utilization Ministry of AgricultureGuangzhou 510300China

The shrimp beam trawl fishery in the northern south china Sea is characterized by high by-catch and poor selectivity *** by-catch species,banded scad(Caranx(Atule)kalla)is economically the most important *** aim of this study is to improve the selective properties of codends for banded *** selectivity of 2 traditional diamond mesh codends,with mesh size 25 and 30 mm(defined as D25 and D30,respectively),and 4 new combined square and diamond mesh codends,with25 mm square-mesh and 25 mm diamond-mesh(S25+D25),30 mm square-mesh and 25 mm diamondmesh(S30+D25),35 mm square-mesh and 25 mm diamond-mesh(S35+D25),and 35 mm square-mesh and18 mm diamond-mesh(S35+D18),were tested for banded scad in shrimp beam trawl fishery of the south china Sea.A total of 54 valid hauls were finished using the covered codend method,and 5750 banded scad were *** parameters were obtained using the logistic equation with the maximum likelihood method,by incorporating the between-haul *** results show that the present minimum mesh size for shrimp beam trawl in the south china Sea,25-mm diamond mesh size,is insufficient to release immature banded *** S35+D25 codend is proved to be the most eff ective codend to release immature banded scad,and its 50%retention length(L _(50))is larger than the minimum landing size(MLS=63.5 mm)of banded ***,the 95%confidence intervals of L _(50) overlap among the three combined mesh codends,the S25+D25,S30+D25 and S35+D25 *** a sustainable exploitation of banded scad,larger mesh sizes are suggested to be investigated for the combined mesh codends.

关键词： shrimp beam trawl diamond mesh codend combined square and diamond mesh codend banded scad Caranx (Alule) kalla size selectivity

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Bird community comparisons of four plantations and conservation concerns in south china

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Integrative Zoology 2014年第1期9卷 97-106页

作者： Fasheng ZOU Qiongfang YANG Yongbiao LIN Guoliang XU Russell GREENBERG Guangdong Entomological Institute GuangzhouChina south china Institute of Endangered Animals GuangzhouChina south china Botanical Garden Chinese Academy of SciencesGuangzhouChina Smithsonian Migratory Bird Centre National Zoological ParkWashingtonDCUSA

Plantations of non-native,fast-growing trees are increasing in the tropics and subtropics,perhaps with negative consequences for the native *** studied bird diversity in 4 types of plantations in south china to deter-mine which plantation types are especially detrimental,and compared our findings with studies in nearby natu-ral forests to assess the magnitude of the negative impact.A total of 57 species was *** mean capture rate of understory birds was 1.7 individuals *** richness and capture rate were lower in plantations than in nearby natural ***(Timaliidae),primarily forest-dependent species in south china,were particularly under-represented in *** richness,composition and bird density,particularly of un-derstory birds,differed between plantation *** of Schima,which is native to south china,had the highest species richness according to point count *** of Acacia(non-native)supported the highest understory species richness and produced the highest capture rate of understory birds,probably because of their complex structure and high arthropod *** bird diversity is to be considered,we strongly recommend that future re-afforestation projects in south china should,as far as possible,use mixed native tree species,and especially Schima,ahead of the other species.

关键词： babbler conservation bird community changing planting ways plantations tree species selection

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Reduction in Activity/Gene Expression of Anthocyanin Degradation Enzymes in Lychee Pericarp is Responsible for the Color Protection of the Fruit by Heat and Acid Treatment

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Journal of Integrative Agriculture 2013年第9期12卷 1694-1702页

作者： FANG Fang ZHANG Zhao-qi ZHANG Xue-lian WU Zhen-xian YIN Hui-fang PANG Xue-qun State Key Laboratory for Conservation and Utilization of Subtropical Agrobioresources/south china agricultural University College of Life Sciences South China Agricultural University College of Horticulture South China Agricultural University

Heat and acid treatments were reported to be a promising substitute for SO2 fumigation in color protection of postharvest lychee （Litchi chinensis） fruits, but the mechanism was not clear. In the present study, hot water （70℃） dipping followed by immersion in 2% HC1 （heat-acid） substantially protected the red color of the fruit during storage at 25℃ and inhibited anthocyanin degradation while hot water dipping alone （heat） led to rapidly browning and about 90% loss in anthocyanin content. The pH values in the pericarp of the heat-acid treated fruit dropped to 3.2, while the values maintained around 5.0 in the heat-treated and control fruit. No significantly different pH values were detected among the arils of heat-acid, heat treated and control fruit. Heat-acid treatment dramatically reduced the activities of anthocyanin degradation enzyme （ADE）, peroxidase （POD） and polyphenol oxidase in the pericarp. A marked reduction in LcPOD gene expression was also detected in heat-acid treated fruit, in contrast, induction was found in heat treated fruit. The pericarp of heat-acid treated fruit exhibited significantly lower respiration rate but faster water loss than that of the untreated or heat treated fruit. Taken together, heat treatment triggered quick browning and anthocyanin loss in lychee fruit, while heat-acid treatment protected the fruit color by a great reduction in the activities/gene expression of anthocyanin degradation enzymes and acidification of lychee pericarp.

关键词： lychee fruit anthocyanin degradation enzymes color retention heat and acid treatment peroxidase geneexpression

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Roles of fishing and climate change in long-term fish species succession and population dynamics in the outer Beibu Gulf,south china Sea

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Acta Oceanologica Sinica 2019年第10期38卷 1-8页

作者： Xuehui Wang Yongsong Qiu Feiyan Du Weida Liu Dianrong Sun Xiao Chen Weiwen Yuan Yong Chen south china Sea Fisheries Research Institute Chinese Academy of Fishery SciencesGuangzhou 510300China Key Laboratory of Open-Sea Fishery Development Ministry of Agriculture and Rural AffairGuangzhou 510300China Guangdong Provincial Key Laboratory of Fishery Ecology and Environment Guangzhou 510300China College of Marine Sciences South China Agricultural UniversityGuangzhou 510642China School of Marine Sciences University of MaineOronoMaine 04469USA Guangxi Academy of Sciences Guangxi Mangrove Research CenterGuangxi Key Lab of Mangrove Conservation and UtilizationBeihai 536000China

A prevailing,controversial hypothesis is that fishing pressure has played a greater role than climatic and environmental drivers,in changing fish species succession and biomass fluctuation in the south china Sea(SCS).Based on otter trawl survey data from 1959 to 2010 in the outer Beibu Gulf(OBG),northern SCS,large seasonal and interannual variation is reported for fish species composition,the proportional abundances of dominant taxa,and fish *** additive models are developed to quantify relationships between fish biomass and the external factors of fishing pressure and climate *** pressure proved to be the main driver of sharp declines in demersal fish stocks,with high-value species being replaced by low-value ones over *** decreases in fish biomass during the years of 1993 and 1998 correspond to El Nino events,with climate change possibly the main driver of proportional representation of pelagic species in fisheries trawl *** need to differentiate impacts of fishing and environmental drivers on fish species with different life history strategies is stressed to better understand fish community dynamics.

关键词： fish species succession biomass fluctuation fishing effect climate influence Beibu Gulf northernsouth china Sea

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Analysis of Genetic Diversity and Population Structure of Maize Landraces from the south Maize Region of china

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agricultural Sciences in china 2010年第9期9卷 1251-1262页

作者： LIU Zhi-zhai GUO Rong-hua ZHAO Jiu-ran CAI Yi-lin WANG Feng-ge CAO Mo-ju WANG Rong- huan SHI Yun-su SONG Yan-chun WANG Tian-yu LI Yu Maize Research Institute Southwest University Chongqing 400716 P.R. China Institue of Crop Sciences/National Key Facility for Gene Resources and Genetic Improvement Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China Maize Research Institute Sichuan Agricultural University Ya＇an 625014 P.R.China Maize Research Center Beijing Academy of Agricultural and Forestry Sciences Beijing 100089 P.R. China

Understanding genetic diversity and population structure of landraces is important in utilization of these germplasm in breeding programs. In the present study, a total of 143 core maize landraces from the south Maize Region （SR） of china, which can represent the general profile of the genetic diversity in the landraces germplasm of SR, were genotyped by 54 DNA microsatellite markers. Totally, 517 alleles （ranging from 4 to 22） were detected among these landraces, with an average of 9.57 alleles per locus. The total gene diversity of these core landraces was 0.61, suggesting a rather higher level of genetic diversity. Analysis of population structure based on Bayesian method obtained the samilar result as the phylogeny neighbor-joining （N J） method. The results indicated that the whole set of 143 core landraces could be clustered into two distinct groups. All landraces from Guangdong, Hainan, and 15 landraces from Jiangxi were clustered into group 1, while those from the other regions of SR formed the group 2. The results from the analysis of genetic diversity showed that both of groups possessed a similar gene diversity, but group 1 possessed relatively lower mean alleles per locus （6.63） and distinct alleles （91） than group 2 （7.94 and 110, respectively）. The relatively high richness of total alleles and distinct alleles preserved in the core landraces from SR suggested that all these germplasm could be useful resources in germplasm enhancement and maize breeding in china.

关键词： maize core landraces genetic diversity population structure

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The deep thermal structure of the lithosphere in the northwestern south china Sea and its control on the shallow tectonics

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Science china Earth Sciences 2021年第6期64卷 962-976页

作者： Xiaofang WANG Haibo HUANG Hehua XU Ziqiang REN Jiazheng ZHANG Zhongxian ZHAO Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyInnovation Academy of South China Sea Ecology and Environmental EngineeringChinese Academy of SciencesGuangzhou511458China southern Marine Science and Engineering Guangdong Laboratory Guangzhou511458China

The northwestern sub-basin of south china Sea(SCS)is a unique tectonic unit formed in the early spreading of the *** northwestern Sub-basin has a series of complex geological structures such as seamounts and fault zones surrounded by the Xisha Trough,the Zhongsha Massif,and the Pearl River *** extensional structures and magmatic activity in the northwestern sub-basin are closely related to the lithospheric structure and its ***,details of the deep lithosphere structure are still poorly ***,we obtained detailed data of water and Moho depth using sonar buoys,Extended Spread Profiles(ESP),Ocean Bottom Seismometer(OBS),both Multi-beam and land-sea joint seismic surveys in the northwestern sub-basin and its surrounding *** we adopted a thermal isostasy method to calculate the depth of the Lithosphere-Asthenosphere Boundary(LAB)in the northwestern sub-basin of the SCS and its surrounding *** show that the range of LAB depth is~25–110 *** shallowest burial depth is 25–60 km occurring in the ocean *** depth increases to 60–110 km toward the continental *** lithospheric structure on the north and south sides of the Xisha Trough is symmetrical and shows the deep structure and thermal features of aborted *** LAB depth in the Zhongsha Trough and the Zhongsha Massif increased from 60 to 70 km southwestwards,consistent with the trend of surface *** LAB depth to the west side of the Pearl River Valley is 60–80 km,and the thinning of the lithosphere is related to the distribution of faults,depressions and the magmatic *** LAB depth in the northwestern sub-basin and the eastern subbasin is less than 60 km with the thinnest part being less than 46 *** ocean drilling,seismic investigation,and seafloor topography,we show that the ocean basin of the northwestern sub-basin of the SCS locates within the 46 km isobath of the *** formation of the rifted valleys and discrete blocks s

关键词： Northwestern sub-basin of SCS Thermal isostasy Ocean-continent transition zone Thickness of lithosphere

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Double [5]carbohelicene: facile synthesis, chiroptical properties,isomerization study, and lasing application

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Science china Chemistry 2025年第1期 233-240页

作者： Peipei Liu Yantong Li Meng-Xiang Wu Hao Kang Xiao-Li Zhao Lin Xu Linlin Liu Xiaodong Li Junfeng Fang Zhiwei Fang Ya Cheng Hai-Bo Yang Huakang Yu Xueliang Shi State Key Laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal University School of Physics and Optoelectronics South China University of Technology Institute of Polymer Optoelectronic Materials & Devices State Key Laboratory of Luminescent Materials & Devices South China University of Technology School of Physics and Electronic Science Engineering Research Center of Nanophotonics & Advanced Instrument Ministry of EducationEast China Normal University State Key Laboratory of Precision Spectroscopy School of Physics and Electronic Science East China Normal University

Double carbohelicenes have attracted considerable attention due to their aesthetic structures, distinct π-conjugation extension, inherent chirality, and intriguing optical and electronic properties. Herein, the concise de novo synthesis of a new double[5]carbohelicene 1 together with its chiroptical properties, isomerization process and lasing application is presented. 1 was synthesized by a simple protocol involving the formation of a 6,6′-bipentacene as the key intermediate. It is worth noting that1 existed as two diastereomers 1-PP/MM and 1-PM, which were successfully isolated and unambiguously confirmed by Xray crystallography. The optical resolution of the racemic 1-PP/MM was successfully achieved by chiral-phase highperformance liquid chromatography（HPLC）, and 1-PP and 1-MM were characterized by circular dichroism. Interestingly, it was found that 1-PP/MM could be completely isomerized to 1-PM upon heating, and the detailed thermodynamics and kinetics of the isomerization process were systematically investigated. 1-PM exhibited deep-red luminescence with emission maximum at 723 nm and fluorescence quantum yield as high as 32.95%. Consequently, we can showcase the lasing application of 1-PM by doping with epoxy resin to assemble a bottle microlaser spontaneously, which the lasing wavelength is 796.6 nm at a threshold of 0.8 m J cm-2. We believe that our studies, including the facile synthesis methodology, detailed isomerization studies, and lasing application, will shed some light on the design and synthesis of novel carbohelical systems with more functions.

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The Recognition of Glycolate Oxidase Apoprotein with Flavin Analogs in Higher Plants

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Acta Biochimica et Biophysica Sinica 2004年第4期36卷 290-296页

作者： Wei-Jun WANG*, Jing-Quan HUANG, Chong YANG, Jiu-Jiu HUANG, and Ming-Qi LI College of Life Science, south china agricultural University, Guangzhou 510642, china College of Life Science South China Agricultural UniversityGuangzhou 510642 China

The dependence of glycolate oxidase apoprotein (apoGO) activity on flavin analogs was surveyed in 9 higher plants from 7 families. Activities of all apoGOs depended not only on flavin mono- nucleotide (FMN) but also on flavin adenine dinucleotide (FAD), but not on riboflavin. The kinetic analysis showed that FMN was the optimum cofactor for apoGO from leaves of Brassica campestris. In plant kingdom, FMN, FAD and riboflavin are three flavin analogs with very similar structure, and they could coexist and be inter-converted from each other, so the question is how the apoprotein of glycolate oxidase (GO) recognized these flavin analogs. No inhibition effect of riboflavin on the activity of apoGO with FMN or FAD was found and no obvious quenching of riboflavin or apoGO protein fluorescence was detected with the addition of apoGO or riboflavin, respectively. These results indicated that riboflavin did not bind to apoGO tightly like FMN and FAD. Inorganic phosphate (Pi) did inhibit the activity of GO, and kinetic analysis revealed that this inhibition was caused by the competitive binding to apoGO between Pi and FMN. This competitive binding was further confirmed by the inhibition of Pi to the quenching of FMN and apoGO protein fluorescence with apoGO and FMN, respectively. It was suggested that the 5’-phosphate group of FMN or FAD may play a key role in the recognition and binding of riboflavin analog cofactors with apoGO.

关键词： glycolate oxidase in higher plant flavin analogs 5’-phosphate moiety recognition

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