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Interactive effects of soil temperature and moisture on soil N mineralization in a Stipa krylovii grassland in Inner Mongolia, China

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Journal of Arid Land 2014年第5期6卷 571-580页

作者： Yue LI YingHui LIU YaLin WANG Lei NIU Xia XU YuQiang tian State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal University Academy of Disaster Reduction and Emergency Management Beijing Normal University College of Resources Science and Technology Beijing Normal University

Determining soil N mineralization response to soil temperature and moisture changes is challenging in the field due to complicated effects from other factors. In the laboratory, N mineralization is highly dependent on temperature, moisture and sample size. In this study, a laboratory incubation experiment was carefully designed and conducted under controlled conditions to examine the effects of soil temperature and moisture on soil N mineralization using soil samples obtained from the Stipa krylovii grassland in Inner Mongolia, China. Five temperature（i.e. 9℃, 14℃, 22℃, 30℃ and 40℃） and five moisture levels（i.e. 20%, 40%, 60%, 80% and 100% WHC, where WHC is the soil water holding capacity） were included in a full-factorial design. During the 71-day incubation period, microbial biomass carbon（MBC）, ammonium nitrogen（NH4 ^＋-N） and nitrate nitrogen（NO3^--N） were measured approximately every 18 days; soil basal respiration for qCO2 index was measured once every 2 days（once a week near the end of the incubation period）. The results showed that the mineral N production and net N mineralization rates were positively correlated with temperature; the strongest correlation was observed for temperatures between 30℃ and 40℃. The relationships between moisture levels and both the mineral N production and net N mineralization rates were quadratic. The interaction between soil temperature and moisture was significant on N mineralization, i.e. increasing temperatures（moisture） enhanced the sensitivity of N mineralization to moisture（temperature）. Our results also showed a positive correlation between the net nitrification rate and temperature, while the correlation between the NH4 ^＋-N content and temperature was insignificant. The net nitrification rate was negatively correlated with high NH4 ^＋-N contents at 80%–100% WHC, suggesting an active denitrification in moist conditions. Moreover, qCO2 index was positively correlated with temperature, especially at 80% WHC. With a low net

关键词： soil N mineralization soil temperature soil moisture Stipa krylovii grassland

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A customized model for 3D human segmental kinematic coupling analysis by optoelectronic stereophotogrammetry

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Science China(Technological Sciences) 2010年第11期53卷 2947-2953页

作者： ZHAO GuoRu REN Lei tian LiMei QIAN ZhiHui WANG Lei REN LuQuan Institute of Biomedical and Health Engineering Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Key Laboratory for Biomedical Informatics and Health Engineering Chinese Academy of SciencesShenzhen 518055China School of Mechanical Aerospace and Civil EngineeringUniversity of ManchesterManchester M601QDUK Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityChangchun 130022China

The study of three-dimensional human kinematics has significant impacts on medical and healthcare technology innovations. As a non-invasive technology, optoelectronic stereophotogrammetry is widely used for in-vivo locomotor evaluations. However, relatively high testing difficulties, poor testing accuracies, and high analysis complexities prohibit its further employment. The objective of this study is to explore an improved modeling technique for quantitative measurement and analysis of human locomotion. Firstly, a 3D whole body model of 17 rigid segments was developed to describe human locomotion. Subsequently, a novel infrared reflective marker cluster for 17 body segments was constructed to calibrate and record the 3D segmental position and orientation of each functional body region simultaneously with high spatial accuracy. In addition, the novel calibration procedure and the conception of kinematic coupling of human locomotion were proposed to investigate the segmental functional characteristics of human motion. Eight healthy male subjects were evaluated with walking and running experiments using the Qualisys motion capture system. The experimental results demonstrated the followings: (i) The kinematic coupling of the upper limbs and the lower limbs both showed the significant characteristics of joint motion, while the torso motion of human possessed remarkable features of segmental motion; (ii) flexion/extension was the main motion feature in sagittal plane, while the lateral bending in coronal plane and the axial rotation in transverse plane were subsidiary motions during an entire walking cycle regarding to all the segments of the human body; (iii) compared with conventional methods, the improved techniques have a competitive advantage in the convenient measurement and accurate analysis of the segmental dynamic functional characteristics during human locomotion. The modeling technique proposed in this paper has great potentials in rehabilitation engineering

关键词： human movement analysis in-vivo skeletal system kinematics calibration technique kinematic coupling

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Degradation induces changes in the soil C:N:P stoichiometry of alpine steppe on the Tibetan Plateau

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Journal of Mountain Science 2019年第10期16卷 2348-2360页

作者： ZHANG Zhen-chao HOU Ge LIU Miao WEI tian-xing SUN Jian School of Soil and Water Conservation Beijing Forestry UniversityBeijing100083China Synthesis Research Centre of Chinese Ecosystem Research Network Key Laboratory of Ecosystem NetworkObservation and ModellingInstitute of Geographic Sciences and Natural Resources ResearchChinese Academy ofSciencesBeijing100101China State Key Laboratory of Urban and Regional Ecology Research Center for Eco–environmental SciencesChineseAcademy of SciencesBeijing100085China Department of Ecology Evolutionand Natural ResourcesSchool of Environmental and Biological SciencesRutgersUniversityNew BrunswickNew Jersey08901USA

Due to the Tibetan Plateau’s unique high altitude and low temperature climate conditions,the region’s alpine steppe ecosystem is highly fragile and is suffering from severe degradation under the stress of increasing population,overgrazing,and climate *** soil stoichiometry,a crucial part of ecological stoichiometry,provides a fundamental approach for understanding ecosystem processes by examining the relative proportions and balance of the three *** the impact of degradation on the soil stoichiometry is vital for conservation and management in the alpine steppe on the Tibetan *** study aims to examine the response of soil stoichiometry to degradation and explore the underlying biotic and abiotic mechanisms in the alpine *** conducted a field survey in a sequent degraded alpine steppe with seven levels inNorthern *** plant species,aboveground biomass,and physical and chemical soil properties such as the moisture content,temperature,pH,compactness,total carbon(C),total nitrogen(N),and total phosphorus(P)were measured and *** results showed that the contents of soil C/N,C/P,and N/P consistently decreased along intensifying degradation *** regression analysis and a structural equation model(SEM),we found that the C/N,C/P,and N/P ratios were positively affected by the soil compactness,soil moisture content and species richness of graminoids but negatively affected by soil pH and the proportion of aboveground biomass of *** soil temperature had a negative effect on the C/N ratio but showed positive effect on the C/P and N/P *** current study shows that degradation-induced changes in abiotic and biotic conditions such as soil warming and drying,which accelerated the soil organic carbon mineralization,as well as the increase in the proportion of forbs,whichwere difficult to decompose and input less organic carbon into soil,resulted in the decreases in soil C/N,C/P,and N/P contents to a great ex

关键词： Tibetan Plateau Alpine steppe Degradation Soil stoichiometry C/N C/P N/P

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Influence of Fluoride Ions on the Structure-directing Effect of Organic Amine in the Synthesis of Aluminophosphate Open-frameworks

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Chemical Research in Chinese Universities 2017年第6期33卷 853-859页

作者： tian Ye XU Jun WANG Zi DENG Feng XU Ruren YAN Wenfu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of Chemistry Jilin University Changchun 130012 P. R. China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Chinese Academy of Sciences Wuhan 430071 P R. China Jilin Province Product Quality Supervision Testing Institute Changchun 130012 P. R. China

The crystallization behavior of the initial mixture with the composition of Al2O3：4.0P2O5：3.0 diethylenetriamine（DETA）：xHF：153H2O was investigated at 180 ℃, where 0≤x≤3. If x≤1.8, three-dimensional openframework aluminophosphate AIPO-CJ31 was obtained. If 2 ≤x≤3, a chain-like aluminophosphate（1） was obtained. The crystallization process of both compounds was investigated by means of powder X-ray diffraction（XRD） and the concentrations of A1 and P in the liquid product during the crystallization process were analysed by means of induc- tively coupled plasma atomic emission spectroscopy（ICP-AES）. The evolution of the coordination state of A1, P and F during the crystallization was monitored with 27A1, 31p and 19F MAS NMR technique. The influence of the fluoride ions and the source of fluoride ions on the structure-directing effect of DETA was discussed. It was found that the fluoride ions changed the crystallization direction of the initial mixture, i.e., the structure-directing effect of DETA, via altering the distribution or micro-structure of the inorganic fragments.

关键词： Zeolite Aluminophosphate Open-framework Structure-directing effect Fluoride

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Tracing the settlement region of massive floating green algae in the Yellow Sea

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Journal of Oceanology and Limnology 2019年第5期37卷 1555-1565页

作者： GENG Huixia YU Rencheng ZHANG Qingchun YAN tian KONG Fanzhou ZHOU Mingjiang Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Ecology and Environmental Science Pilot National Laboratory for Marine Science and Technology (Qingdao)Qingdao 266237China University of Chinese Academy of Sciences Beijing 100049China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Outbreaks of large-scale green tides formed by Ulva prolifera in the Yellow Sea (YS) cause heavy ecological damages and huge economic losses. However, the ecological consequences of green tides remain poorly understood due to the lack of knowledge on the settlement region of massive green algae floating in the YS. In this study, we established a method to trace the settlement region of floating green algae, using 28-isofucosterol preserved in sediment as the specific biomarker for green algae. Sterols including 28-isofucosterol in surface sediment samples collected during an investigation in the YS and the Bohai Sea (BS) in August 2015 were analyzed using gas chromatography coupled with a mass spectrometer (GC-MS). Based on the content of 28-isofucosterol in sediment samples, the potential settlement region of fl oating green algae was identifi ed in the sea area southeast to the Shandong Peninsula around the sampling site H06 (122.66°E, 36.00°N). This paper presents a first result on the settlement region of floating green algae in the YS for providing a solid basis to elucidate the ecological consequences of green tides in the area.

关键词： green tide biomarker sterol Ulva prolifera

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Supramolecular adhesive materials from small‐molecule self‐assembly

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SmartMat 2020年第1期1卷 85-103页

作者： Chen‐Yu Shi Qi Zhang He tian Da‐Hui Qu Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Feringa Nobel Prize Scientist Joint Research CenterFrontiers Science Center for Materiobiology and Dynamic ChemistrySchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghaiChina

Developing high‐performance adhesive materials not only aims at industrial and social requirements but also bears the fundamental importance of understanding the chemical factors of biological adhesion to develop biomimetic adhesive *** to the wide development of supramolecular chemistry,numerous supramolecular tools are exploited and proved to be reliable in the replacement of traditional covalent materials by reversible noncovalent or dynamic covalent *** advantage of these readyto‐use supramolecular toolboxes,supramolecular adhesive materials are rising and promising toward“smart”adhesives,that is,enabling responsiveness,reversibility,and *** with polymeric adhesive materials,low‐molecular‐weight adhesives feature chemically precise structure,easier engineering by molecular design,and hence higher ***,it remains highly challenging to make high‐performance adhesive materials by low‐molecular‐weight *** review will focus on the recent advancement in the construction of supramolecular adhesive materials by smallmolecule self‐*** design guidelines and consideration on the molecular scale will be discussed and summarized on how to enhance the strength of ***,owing to the dynamic nature of supramolecular self‐assembly,several“smart”functions of such materials will be presented,such as stimuli–responsiveness and ***,current challenges and future perspectives of this emerging field will be proposed.

关键词： adaptiveness responsiveness small‐molecule self‐assembly supramolecular adhesive materials

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Flume experimental study on evolution of a mouth bar under interaction of floods and waves

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Water Science and Engineering 2019年第2期12卷 162-168页

作者： Li Yan Men-wu Wu Ying Chen Yao Wu tian-sheng Wu Pearl River Hydraulic Research Institute Pearl River Water Resources CommissionGuangzhou 510611China Key Laboratory of the Pearl River Estuarine Dynamics and Associated Process Regulation Ministry of Water ResourcesGuangzhou 510610China College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China

Based on the characteristics of hydrodynamics and sediment transport in the bar area in the Modaomen Estuary,a flume experiment was performed to study the evolution of the longitudinal profile of the mouth *** mouth bar evolution was investigated under the impacts of floods with different return periods as well as flood-wave *** results showed that floods with different return periods had significant influences on the evolution of the river mouth *** on the inner slope of the mouth bar,the sediment was substantially active and *** inner slope and the bar crest tended to be remarkably *** erosion was intensified with the increase of the magnitude of ***,the bar crest moved seawards,while the elevation of the bar crest barely *** the flood-wave interaction,a remarkable amount of erosion on the inner and outer slopes of the mouth bar was also *** seaward displacement of the bar crest under the interaction of floods and waves was less than it was under only the impact of floods,while more deposition was found on the crest of the mouth bar in this case.

关键词： Modaomen Mouth bar Wave Flood Flume experiment Sediment transport

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Application and improvement of an adaptive ensemble Kalman filter for soil moisture data assimilation

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Science China Earth Sciences 2010年第11期53卷 1700-1708页

作者： Shi XiaoKang Wen Jun Liu JianWen tian Hui Wang Xin Li YaoDong Chinese Acad Sci Cold & Arid Reg Environm & Engn Res Inst Lab Climate Environm & Disasters Western China Lanzhou 730000 Peoples R China Beijing Aviat Meteorol Inst Beijing 100085 Peoples R China

Accurate assignment of model and observation errors is crucial for the successful application of land surface data assimilation algorithms. Poorly-specified model and observation errors can significantly degrade assimilation results. In 2008, Reichle et al. developed an operational procedure to adaptively tune model and observation errors. In this paper, we modified and applied Reichle's procedure in the Noah land surface model to assimilate observed surface soil moisture data. Numerical simulations showed that: (1) the best estimate of model and observation errors appears when the empirical factor β equals 1.02; (2) the Reichle procedure can be deployed to adaptively tune errors if their true values change slowly; and (3) convergence of the Reichle procedure was improved using better initial errors achieved by iterative computations.

关键词： Noah numerical simulation data assimilation adaptive ensemble Kalman filter soil moisture

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Cryo-electron microscopy reconstructions of two types of wild rabbit hemorrhagic disease viruses characterized the structural features of Lagovirus

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Protein & Cell 2010年第1期1卷 48-58页

作者： Zhongjun Hu Xiaojuan tian Yujia Zhai Wei Xu Dong Zheng Fei Sun National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing 100101China Department of Biochemistry and Molecular Biology College of Life SciencesBeijing Normal UniversityBeijing 100875China

Rabbit hemorrhagic disease was described in China in 1984 and can cause hemorrhagic necrosis of the liver within two or three days after *** etiological agent,rabbit hemorrhagic disease virus(RHDV),belongs to the Lagovirus genus in the Caliciviridae *** to other calicivirus,such as rNV and SMSV,the structure of Lagovirus members is not well *** this report,structures of two types of wild RHDV particles,the intact virion and the core-like particle(CLP),were reconstructed by cryo-electron microscopy at 11Åand 17Å,*** is the first time the 3D structure of wild caliciviruses CLP has been provided,and the 3D structure of intact RHDV virion is the highest resolution structure in *** of the intact virion and CLP structures clearly indicated that CLP was produced from the intact virion with the protrusion *** contrast with the crystal structures of recombinant Norovirus and San Miguel sea lion virus,the capsomers of RHDV virion exhibited unique structural features and assembly *** P1 and P2 subdomains have interactions inside the AB capsomer,while only P2 subdomains have interaction inside CC *** pseudo atomic models of RHDV capsomers were constructed by homology modeling and density map fitting,and the rotation of RHDV VP60 P domain with respect to its S domain,compared with SMSV,was ***,our cryo-electron microscopic studies of RHDV provide close insight into the structure of Lagovirus,which is important for functional analysis and better vaccine development in the future.

关键词： rabbit hemorrhagic disease virus calicivirus Lagovirus core-like particle cryo-electron microscopy reconstruction

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DTI and pathological changes in a rabbit model of radiation injury to the spinal cord after ^(125)I radioactive seed implantation

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Neural Regeneration Research 2018年第3期13卷 528-535页

作者： Xia Cao Le Fang Chuan-yu Cui Shi Gao tian-wei Wang School of Pharmaceutical Sciences Jilin University First Department of Neurology China-Japan Union Hospital of Jilin University Department of MRI Fourth Hospital Jilin University Department of Nuclear Medicine China-Japan Union Hospital of Jilin University Department of Radiology China-Japan Union Hospital of Jilin University

Excessive radiation exposure may lead to edema of the spinal cord and deterioration of the nervous system. Magnetic resonance imaging can be used to judge and assess the extent of edema and to evaluate pathological changes and thus may be used for the evaluation of spinal cord injuries caused by radiation therapy. Radioactive ^125I seeds to irradiate 90% of the spinal cord tissue at doses of 40–100 Gy （D90） were implanted in rabbits at T10 to induce radiation injury, and we evaluated their safety for use in the spinal cord. Diffusion tensor imaging showed that with increased D90, the apparent diffusion coefficient and fractional anisotropy values were increased. Moreover, pathological damage of neurons and microvessels in the gray matter and white matter was aggravated. At 2 months after implantation, obvious pathological injury was visible in the spinal cords of each group. Magnetic resonance diffusion tensor imaging revealed the radiation injury to the spinal cord, and we quantified the degree of spinal cord injury through apparent diffusion coefficient and fractional anisotropy.

关键词： nerve regeneration brachytherapy ^125I radioactive seeds magnetic resonance imaging radiation injury of the spinal cord diffusion tensor imaging apparent diffusion coefficient fractional anisotropy neural regeneration

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