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Nitrogen cycling of atmosphere-plant-soft system in the typical Calamagrostis angustifolia wetland in the Sanjiang Plain,Northeast China

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Journal of Environmental Sciences 2007年第8期19卷 986-995页

作者： SUN Zhi-gao LIU jing-shuang Northeast Institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130012 China. Graduate University of Chinese Academy of Sciences Beijing 100039 China Yantai Institute of Coastal Zone Research for Sustainable Development Chinese Academy of Sciences Yantai 264003 China

The nitrogen （N） distribution and cycling of atmosphere-plant-soil system in the typical meadow Calamagrostis angustifolia wetland （TMCW） and marsh meadow Calamagrostis angustifolia wetland （MMCW） in the Sanjiang plain were studied by a compartment model. The results showed that the N wet deposition amount was 0.757 gN/（m^2·a）, and total inorganic N （TIN） was the main body （0.640 gN/（m^2·a））. The ammonia volatilization amounts of TMCW and MMCW soils in growing season were 0.635 and 0.687 gN/m^2, and the denitrification gaseous lost amounts were 0.617 and 0.405 gN/m^2, respectively. In plant subsystem, the N was mainly stored in root and litter. Soil organic N was the main N storage of the two plant-soil systems and the proportions of it were 93.98% and 92.16%, respectively. The calculation results of N turnovers among compartments of TMCW and MMCW showed that the uptake amounts of root were 23.02 and 28.18 gN/（m^2·a） and the values of aboveground were 11.31 and 6.08 gN/（m^2·a）, the re-translocation amounts from aboveground to root were 5.96 and 2.70 gN/（m^2·a）, the translocation amounts from aboveground living body to litter were 5.35 and 3.38 gN/（m^2·a）, the translocation amounts from litter to soil were larger than 1.55 and 3.01 gN/（m^2·a）, the translocation amounts from root to soil were 14.90 and 13.17 gN/（m^2·a）, and the soil （0-15 cm） N net mineralization amounts were 1.94 and 0.55 gN/（m^2·a）, respectively. The study of N balance indicated that the two plant-soil systems might be situated in the status of lacking N, and the status might induce the degradation of C. angustifolia wetland.

关键词： compartment model nitrogen cycling Calamagrostis angustifolia wetland ecosystem Sanjiang Plain

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Distribution and Fate of Anthropogenic Nitrogen in the Calamagrostis angustifolia Wetland Ecosystem of Sanjiang Plain, Northeast China

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Journal of Integrative Plant Biology 2008年第4期50卷 402-414页

作者： Zhi-Gao Sun jing-shuang Liu Northeast Institute of Geography and Agricultural Ecology the Chinese Academy of Sciences Changchun 130012 China Graduate School of the Chinese Academy of Sciences Beijing 100039 China

Wetlands are important for the protection of water quality of rivers and lakes, especially those adjacent to agricultural landscapes, by intercepting and removing nutrients in runoff. In this study, the ^15N tracer technique was applied to study the distribution and fate of anthropogenic nitrogen （^15N-fertilizer） in Calamagrostis angustifolia Kom wetland plant-soil microcosms to identify the main ecological effects of it. ^15NH4^15NO3 solution （14.93 mg N/L, 20.28 at.% ^15N） was added to each microcosm of the first group, which was approximate to the current nitrogen concentration （CNC） of farm drainage, and 29.86 mg NIL ^15NH4^15NO3 solution was added to another group, which was approximate to the double nitrogen concentration （DNC） of farm drainage, while no nitrogen （NN） was added to the third group. The results suggest that the input of anthropogenic nitrogen has positive effects on the biomass and total nitrogen content of plant, and the positive effects will be elevated as the increase of its input amount. The increase of ^15N-fertilizer can also elevate its amounts and proportions in plant nitrogen. Soil nitrogen is still the main source of plant nitrogen, but its proportion will be reduced as the increase of ^15 N-fertilizer. The study of the fate of ^15N-fertilizer indicates that, in CNC treatment, only a small proportion is water-dissolved （0,13 ± 0.20%）, a considerable proportion is soil-immobilized （17.02 ± 8.62%）, or plant-assimilated （23.70 ± 0.92%）, and most is lost by gaseous forms （59.15 ± 8.35%）. While in DNC treatment, about 0.09 ± 0.15% is water-dissolved, 15.33 ± 7.46% is soil-immobilized, 23.55±2.86% is plant-assimilated, and 61.01±5.59% is lost by gaseous forms. The double input of anthropogenic nitrogen can not elevate the proportions of plant-assimilation, soil-immobilization and water-dissolution, but it can enhance the gaseous losses.

关键词： ^15N Tracer technique agricultural runoff Calamagrostis angustifolia wetland distribution and fate Sanjiang Plain.

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Real-time prediction of tunnel face conditions using XGBoost Random Forest algorithm

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Frontiers of Structural and Civil Engineering 2023年第12期17卷 1777-1795页

作者： Lei-jie WU Xu LI Ji-dong YUAN shuang-jing WANG Key Laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China School of Computer and Information Technology Beijing Jiaotong UniversityBeijing 100044China

Real-time perception of rock conditions based on continuously collected data to meet the requirements of continuous Tunnel Boring Machine(TBM)construction presents a critical challenge that warrants increased *** achieve this goal,this paper establishes real-time prediction models for fractured and weak rock mass by comparing 6 different algorithms using real-time data collected by the *** models are optimized in terms of selecting metric,selecting input features,and processing imbalanced *** results demonstrate the following points.(1)The Youden's index and area under the ROC curve(AUC)are the most appropriate performance metrics,and the XGBoost Random Forest(XGBRF)algorithm exhibits superior prediction and generalization performance.(2)The duration of the TBM loading phase is short,usually within a few minutes after the disc cutter contacts the tunnel face.A model based on the features during the loading phase has a miss rate of 21.8%,indicating that it can meet the early warning needs of TBM construction *** the TBM continues to operate,the inclusion of features calculated from subsequent data collection can continuously correct the results of the real-time prediction model,ultimately reducing the miss rate to 16.1%.(3)Resampling the imbalanced data set can effectively improve the prediction by the model,while the XGBRF algorithm has certain advantages in dealing with the imbalanced data *** the model gives an alarm,the TBM operator and on-site engineer can be reminded and take some necessary measures for avoiding potential tunnel *** real-time predication model can be a useful tool to increase the safety of TBM excavation.

关键词： Tunnel Boring Machine fractured and weak rock mass machine learning model real-time early warming tunnel facerockcondition

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Transition-metal-free synthesis of 1,4-benzoxazepines via[4+3]-cycloaddition of para-quinone methides with azaoxyallyl cations

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Science China Chemistry 2021年第1期64卷 61-65页

作者： shuang-jing Zhou Xiao Cheng Chun-Xia Hu Guo-Yong Xu Wen-jing Xiao Jun Xuan Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials and Key Laboratory of Functional Inorganic Materials of Anhui Province College of Chemistry&Chemical EngineeringAnhui UniversityHefei 230601China Key Laboratory of Structure and Functional Regulation of Hybrid Materials(Anhui University) Ministry of EducationHefei 230601China Key Laboratory of Pesticide&Chemical Biology Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhan 430079China AInstitute of Physical Science and Information Technology Anhui University.Hefei 230601China

A formal[4+3]-cycloaddition reaction of ortho-hydroxyphenyl-substituted para-quinone methides(p-QMs)with in-situ generated azaoxyallyl cations is *** reaction occurs under very mild reaction conditions(transition-metal free,room temperature,cheap inorganic base)and provides a very efficient route to a series of biologically important 1,4-benzoxazepine derivatives in good to excellent yields.

关键词： 1,4-benzoxazepines para-quinone methides azaoxyallyl cations cycloaddition transition-metal-free

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Solving elastic wave equations in 2D transversely isotropic media by a weighted Runge-Kutta discontinuous Galerkin method

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Petroleum Science 2023年第2期20卷 827-839页

作者： Xi-Jun He jing-shuang Li Xue-Yuan Huang Yan-Jie Zhou School of Mathematics and Statistics Beijing Technology and Business University(BTBU)Beijing100048China School of Science China University of Mining and Technology(Beijing)Beijing100083China

Accurate wave propagation simulation in anisotropic media is important for forward modeling, migration and inversion. In this study, the weighted Runge-Kutta discontinuous Galerkin (RKDG) method is extended to solve the elastic wave equations in 2D transversely isotropic media. The spatial discretization is based on the numerical flux discontinuous Galerkin scheme. An explicit weighted two-step iterative Runge-Kutta method is used as time-stepping algorithm. The weighted RKDG method has good flexibility and applicability of dealing with undulating geometries and boundary conditions. To verify the correctness and effectiveness of this method, several numerical examples are presented for elastic wave propagations in vertical transversely isotropic and tilted transversely isotropic media. The results show that the weighted RKDG method is promising for solving wave propagation problems in complex anisotropic medium.

关键词： Discontinuous Galerkin method Anisotropy Transversely isotropic Modeling

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Condensation of phenol and acetone on a modified macroreticular ion exchange resin catalyst

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Frontiers of Chemical Science and Engineering 2013年第2期7卷 218-225页

作者： Baohe WANG Lili WANG jing ZHU shuang CHEN Hao SUN Key Laboratory for Green Chemical Technology of Ministry of Education Research and Development Center of Petrochemical Technology Tianjin University Tianjin 300072 China

Macroreticular ion exchange resin catalysts were prepared by suspension polymerization, and then modified by alkylmercaptoamines. The modified catalysts were characterized by N2 adsorption/desorption measure- ments, scanning electron microscopy and differential scanning calorimetry. Key factors such as the mercaptan content, the degree of crosslinking and the structures of the promoters were investigated for the synthesis of Bisphenol A （BPA）. At optimal conditions, the macroreticular ion exchange resin catalysts modified by alkylmercaptoamines showed high catalytic activity and selectivity for BPA synthesis.

关键词： macroreticular ion exchange resin catalysts,suspension polymerization Bisphenol A

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MULTI-AGENT COMPUTER AIDED ASSEMBLY PROCESS PLANNING SYSTEM FOR SHIP HULL

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Chinese Journal of Mechanical Engineering 2001年第1期14卷 57-61页

作者： Zhang Shijie jing shuang Shenyang Institute of Automation, Chinese Academy of Sciences 中科院沈阳自动化所辽宁沈阳

A multi agent computer aided assembly process planning system (MCAAPP) for ship hull is presented. The system includes system framework, global facilitator, the macro agent structure, agent communication language, agent oriented programming language, knowledge representation and reasoning strategy. The system can produce the technological file and technological quota, which can satisfy the production needs of factory.

关键词： Multi agent Intelligent agent Computer aided process planning Knowledge representation

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Effects of Wetland Reclamation on Soil Nutrient Losses and Reserves in Sanjiang Plain,Northeast China

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Journal of Integrative Agriculture 2012年第3期11卷 512-520页

作者： WANG Yang LIU jing-shuang WANG Jin-da SUN Chong-yu Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130012P.R.China

The carbon （C）, nitrogen （N） and phosphorus （P） variations of a temperate wetland soil under continuous cultivation for 40 yr were determined and evaluated in the Sanjiang Plain, Northeast China. The results showed that the soil organic carbon （SOC） and total nitrogen （TN） contents in each soil layer decreased sharply after cultivation for 2-3 yr, and exhibited minor differences after cultivation for 11 yr, which showed an exponential decline curve with the increase of cultivation years. The reduction rates of carbon and nitrogen reserves were 14.79% and 28.53% yr^-1 at the initial reclamation stages of 2-3 yr and then decreased to 2.02-3.08% yr^-1 and 1.98-2.93% yr^-1 after cultivation for 20 yr, respectively. Soil total phosphorus （TP） reserves decreased within cultivation for 5 yr, and then gradually restored to the initial level after cultivation for 17 yr. Both SOC and TN could be restored slightly when the farmland was left fallow for 8 yr after reclamation for 11 yr, whereas TP had no significant difference. These results demonstrated that wetland cultivation was one of the most important factors influencing on the nutrient fate and reserves in soil, which could lead to the rapid nutrient release and slow restoration through abandon cultivation, therefore protective cultivation techniques preventing nutrients from loss should be immediately established after wetland reclamation.

关键词： wetland reclamation Sanjiang Plain organic carbon total nitrogen total phosphorus

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Responses of the ocean carbon cycle to climate change: Results from an earth system climate model simulation

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Advances in Climate Change Research 2014年第3期5卷 123-130页

作者： WANG shuang-jing CAO Long LI Na Department of Earth Sciences Zhejiang University

Based on simulations using the University of Victoria's Earth System Climate Model, we analyzed the responses of the ocean carbon cycle to increasing atmospheric CO2 levels and climate change from 1800 to 2500 following the RCP 8.5 scenario and its extension. Compared to simulations without climate change, the simulation with a climate sensitivity of 3.0 K shows that in 2100, due to increased atmospheric CO2 concentrations, the simulated sea surface temperature increases by 2.7 K, the intensity of the North Atlantic deep water formation reduces by4.5 Sv, and the oceanic uptake of anthropogenic CO2 decreases by 0.8 Pg C. Climate change is also found to have a large effect on the North Atlantic's ocean column inventory of anthropogenic CO2. Between the years 1800 and 2500, compared with the simulation with no climate change, the simulation with climate change causes a reduction in the total anthropogenic CO2 column inventory over the entire ocean and in North Atlantic by 23.1% and 32.0%, respectively. A set of simulations with climate sensitivity variations from 0.5 K to 4.5 K show that with greater climate sensitivity climate change would have a greater effect in reducing the ocean's ability to absorb CO2 from the atmosphere.

关键词： Climate change Ocean carbon cycle Carbon cycle modeling

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Verticase:a Fibrinolytic Enzyme Produced by Verticillium sp,Tj33,an Endophyte of Trachelospermum jasminoides

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Journal of Integrative Plant Biology 2007年第11期49卷 1548-1554页

作者： Ying Li jing-Lei shuang Wei-Wei Yuan Wu-Yang Huang Ren-Xiang Tan College of Horticulture Nanjing Agricultural University Nanjing 210095 China Institute of Functional Biomolecules Nanjing University Nanjing 210093 China

Plant endophytes are among the most important resources of biologically active metabolites. Twenty-three endophyte strains residing in Trachelospermum jasminoides were cultivated in vitro with the cultures assayed for the fibrinolytic substance production. As a result, the culture of VerticUlium sp. Tj33 was shown to be the most active. A fibrinolytic enzyme designated as verticase was subsequently purified from the supernatant of Verticillium sp. culture broth by a combination of DEAE-52, Sephadex G-75 and hydrophobic column chromatographies. Verticase, with its molecular mass of 31 kDa and pl of 8.5, was demonstrated to be homogeneous by sodium dodecyl suIfate-polyacrylamide gel electrophoresis and isoelectric focusing electrophoresis. Verticase is an enzyme that hydrolyzes fibrin directly without activation of plaminogen. It was stable in a broad pH range from 4 through to 11 with the optimal reaction pH value and temperature shown to be around 9-10 and 50-60℃, respectively. The fibrinolytic activity of verticase was severely inhibited by phenylmethylsulfony fluoride, indicating that verticase was a serine protease.

关键词： fibrinolytic serine protease plant endophyte protein purification Trachelosperrnum jasminoides verticase.

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