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Changes in Soil Biota Resulting from Growth of the Invasive Weed, Ambrosia artemisiifolia L.(Compositae), Enhance Its Success and Reduce Growth of Co-Occurring Plants

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Journal of Integrative Agriculture 2014年第9期13卷 1962-1971页

作者： LI hui-na XIAO Bo LIU wan-xue wan Fang-hao State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant Protection Chinese Academy of Agricultural Sciences

Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plant Ambrosia artemisiifolia L. facilitates its competition capacity through changing the structure and function of soil microbial communities. The soil characteristics of different areas invaded by A. artemisiifolia were examined. Greenhouse experiments were designed to assess the effect of A. artemisiifolia invasion-induced changes of soil biota on co-occurring plant growth, and on the interactions between A. artemisiifolia and three co-occurring plant species. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites. Soil available N, P and K concentrations in heavily invaded site were 2.4, 1.9 and 1.7 times higher than those in native plant soil, respectively. Soil pH decreased as A. artemisiifolia invasion intensity increased, and was lower in invaded sites（heavily invaded and newly invaded） than in native plant sites. The soil microbial community structure was clearly separated in the three types of sites, and A. artemisiifolia invasion increased anaerobe, sulfate-reducing bacteria and actinomycete abundance. Soil biota of invaded sites inhibits growth of co-occurring plants（Galinsoga parvifloraCav., Medicago sativa L. and Setaria plicata（Lam.） T. Cooke.） compared to soil biota from un-invaded sites, but facilitates A. artemisiifolia growth and competition with co-occurring plants. A. artemisiifolia biomass was 50-130% greater when competing with three co-occurring plants, compared to single-species competition only（invasion by A. artemisiifolia alone）, in heavily invaded soil. Results of the present study indicated that A. artemisiifolia invasion al

关键词： biological invasion invasive alien plant Ambrosia artemisiifolia L. soil biota soil fertility

A clinical study to determine the threshold of bronchodilator response for diagnosing asthma in Chinese children

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World Journal of Pediatrics 2019年第6期15卷 559-564页

作者： Xiao-hui Kang wan wang Ling Cao Children's Hospital Affiliated to the Capital Institute of Pediatrics No.2 Ya bao RoadChaoyang DistrictBeijingChina Shanxi Provincial Children's Hospital TaiyuanChina

Background There is few objective,clinically feasible and inexpensive test for diagnosing childhood *** want to find an ideal way to solve *** The control group was 301 non-asthmatic children,and the asthma group was 286 asthmatic *** asthmatic children were divided into three groups according to the severity of their ***-and post-bronchodilator spirometer tests were performed,and the main spirometer parameters were *** bronchodilator response(BDR)[BDR is used to determine the reversibility of airway obstruction by measuring the changes of forced expiratory volume in the first second(FEV1)before and after inhalation of bronchodilators]was then determined,and the optimal threshold of BDR for diagnosing childhood asthma was *** 301 non-asthmatic children and 286 asthmatic children participated in the study,the demographics were *** 1 for pre-bronchodilator of asthmatic children was significantly lower than that of non-asthmatic children(P≤0.01).BDR of non-asthmatic children was 3.30±3.85%.BDR of asthmatic children was 9.45±9.15%.There was no significant difference in BDR for patients with different severities of asthma within the *** had no statistical correlation with gender,age,height,weight in neither non-asthmatic children nor asthmatic *** the receiver-operating characteristic curve,a BDR threshold of≥7.5%offered an optimal balance in asthma diagnosis with a sensitivity rate of 50.7%and specificity rate of 87.7%.Meanwhile,with a BDR threshold of≥12%,the sensitivity rate was 28.7%and the specificity rate was 96.3%.Conclusion A BDR threshold of≥7.5%has more value in childhood asthma diagnosis as compared to≥12%.

关键词： Asthma diagnosis Bronchodilator response Threshold

Mechanical properties and microstructure of in situ formed Ti_(2)AlN/TiAl(WMS)composites

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Rare Metals 2021年第1期40卷 190-194页

作者： wan-Liang Liang Rui Hu Yi-Wen Liu Tie-bang Zhang Jin-Shan Li State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China

The Ti_(2)AlN-reinforced TiAl(WMS)composites with different contents of Ti_(2)AlN were prepared by an in situ method of reactive arc-melting *** to the results of X-ray diffraction(XRD)analysis,the Ti_(2)AlNreinforced WMS composites consist ofγ-TiAl,α_(2)-Ti_(3)Al,and Ti_(2)AlN *** analysis results indicate that Ti_(2)AlN reinforcements with rod-like in shape form in the WMS matrix with aα_(2)/γlamellar structure containing some bulk y *** volume fraction of Ti_(2)AlN increasing,the grain size of the composites decreases significantly and the elasticity modulus(E)*** compressive strength and compressive fracture strain of the composite with 3 vol%Ti_(2)AlN have a maximum value of 1,654 MPa and 22.5%,respectively,which are approximately improved by 45.84%and 29.31%,respectively,compared with that of the unreinforced WMS alloy.

关键词： Ti_(2)AlN/TiAl(WMS)composites Reactive arc-melting Microstructure Compressive properties

Synthesis and Properties of pH and Temperature Responsive Copolymer with Pesudorotaxane Structure

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Chemical Research in Chinese Universities 2012年第6期28卷 1101-1106页

作者： MA Qiang YANG hui XU Wen-chao TAN Ye-bang Key Laboratory of Special Functional Aggregated Materials Ministry of EducationSchool of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China

pH and temperature responsive copolymers PNAM4VBCB of N-isopropyl acrylamide（NAM） and complex pseudorotaxane monomer N 1-（4-vinylbenzyl）-1,4-diaminobutane dihydrochloride with cucurbit[6]uril（CB[6]） threaded（4VBCB） were prepared via free-radical polymerization in aqueous *** copolymers were characterized by 1 H NMR,Fourier transform infrared（FTIR） spectrometry,elemental analysis,and static light *** thermodynamic properties of the copolymers were studied by thermogravimetric analysis（TGA）,and the effects of pH and the concentration of the copolymer on the average hydrodynamic radius（R h） were studied by dynamic light scattering（DLS）.In addition,the thermal sensitivities of the copolymers were studied by DLS and *** experiment data show that CB[6] beads are localized on 1,4-diaminobutane units in the side chains of the *** data show that thermal stability of the copolymers increases with the adding of CB[6] threaded because of the enhanced rigidity and the bulky steric hindrance of 4VBCB in the side chain of *** data show that the average hydrodynamic radius of copolymer increases with the increase of the copolymer concentration and has a jump with adjusting pH due to the existing of the small size CB[6] dethreaded from the copolymer with increasing *** pH and electrical conductivity curves of the solution of PNAM4VBCB-4 have a jump because CB[6] could dethread from the copolymers with the addition of *** addition,the copolymers have thermal sensitivity and their phase-change temperatures could be controlled by adjusting the molar ratio of NAM to 4VBCB in the copolymers.

关键词： Cucurbituril Thermal sensitivity Water soluble copolymer Polypseudorotaxane

Density Functional Theory Study on Spin States of LaCoO3 at Room Temperature

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Chinese Journal of Chemical Physics 2014年第3期27卷 274-278页

作者： Xiang-bo Zhang Gang Fu hui-lin wan State Key Laboratory for Physical Chemistry of Solid Surfaces Department of Chemistry College ofChemistry & Chemical Engineering Xiamen University Xiamen 361005 China

The electronic structure of the perovskite LaCoO3 at room temperature structure （293 K） was calculated by using PBE, PBE＋U and HSE. Different spin configurations have been considered. Our calculations showed that the choice of the Hubbard U parameter in DFT＋U and mixing factor α in HSE significantly influenced the band gap as well as relative energies. For the spin exited states, the optimal value for U and α were 3.0 eV and 0.05, respectively. Our calculation also emphasized that when U〉5.0 eV, PBE＋U would lead to unreasonable electronic structure and energy order.

关键词： Perovskite LaCoO3 Density functional theory

Does the long-term application of calcium superphosphate lead to an increase of the soil rare earth element contents？

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Journal of Environmental Sciences 2006年第1期18卷 130-134页

作者： ZHANG Yun DENG Li-bin YE wan-hui South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China School of Resources and Environmental Science Hubei University Wuhan 430062 China Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

In order to test whether the long-term application of calcium superphosphate leads to an increase of the soil rare earth element contents, superphosphate fertilized soils were sampled and compared with superphosphate-free soils. Spectrophlame inductively coupled argon plasma atomic emission spectrophotometer （ICP-AES） was applied to quantify the rare earth elements （REEs）. The total rare earth element contents in calcium superphosphate from Zhijin County, west part of Guizhou Province, China （produced by the sulphuric acid treatment of the apatites） are about 2.54 mg/g. Between 38 and 189 gREEs/hm^2 per year （available for plants, estimated by 2% citric acid） will be introduced into the soil solution when applying 320 kg superphosphate/hm^2 per year. The long-term application of the latter will increase the REE content by about 18% in the soil surface layer in these areas. A statistically significant increase of the content of the rare earths in some cultivated soils should not be neglected.

关键词： rare earth elements calcium superphosphate soil

Science Letters:Nitrogen doping of activated carbon loading Fe_2O_3 and activity in carbon-nitric oxide reaction

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 707-711页

作者： wan Xian-kai ZOU Xue-quan SHI hui-xiang wanG Da-hui Institute of Environmental Engineering Zhejiang University Hangzhou 310027 China

Nitrogen doping of activated carbon loading Fe2O3 was performed by annealing in ammonia, and the activity of the modified carbon for NO reduction was studied in the presence of oxygen. Results show that Fe2O3 enhances the amount of surface oxygen complexes and facilitates nitrogen incorporation in the carbon, especially in the form of pyridinic nitrogen. The modified carbon shows excellent activity for NO reduction in the low temperature regime （〈500℃） because of the cooperative effect of Fe2O3 and the surface nitrogen species.

关键词： Activated carbon Nitric oxide Doping Iron oxides Catalytic reduction

Synthesis,Spectroscopic Properties and Structural Characterization of Sodium Potassium Citrato Oxotungstate(VI)Dimer

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Chinese Journal of Structural Chemistry 2000年第3期19卷 181-186页

作者： wanG Geng ZHOU Zhao-hui ZHANG hui YE Jian-Liang wan hui-Lin Department of Chemistry and State Key Laboratory for Physical Chemistry of Solid Surface Xiamen UniversityXiamen361005

The sodium potassium citrato oxotungstate(VI) dimer, Na 4K 2〔W 2O 5\|(cit) 2〕·11H 2O (H 4cit = citric acid) was obtained by the reaction of sodium tungstate(VI) and excess potassium citrate monobasic (KH 3cit) in neutral solution. The crystal data for the title compound: monoclinic, C 12 H 30 K 2Na 4W 2O 30 , M r =1192.21, space group P2 1/n, a=17.427(4), b=10.022(2), c=18.637(3) , β=92.62(1)°, V=3252(2)  3, Z=4, D c =2.435 g/cm 3, μ( Mo Kα )=76.38 cm -1 , F( 000)=2288. The structure was refined to R =0.0434 for 6327 independent observed reflections with I>3σ(I) . The complex anion contains a quasi centrosymmetric (O 2W)O b(WO 2) core with a bent bridging oxo group 〔W-O b-W 175.0(4)°〕. Each citrate as tridentate ligand coordinates to a tungsten atom through the alkoxy, α carboxyl, and one β carboxyl group, while the other β carboxyl group remains uncoordinated. Principal dimensions are: W-O b 1.883(6) , (W=O t)av 1.715(6) , W-O (alkoxy) 1.959(6) , W-O ( α carboxy) 2.176(6)  and W-O ( β carboxy) 2.231(6) . The tungsten atom is located in a distorted octahedron environment.

关键词： oxotungstate(VI) citrate citric acid citrate method crystal structure

Optimization of the S-band side-coupled cavities for proton acceleration

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Nuclear Science and Techniques 2020年第3期31卷 1-9页

作者： Hao-Yun Li Xin-Miao wan Wei Chen Chen-hui Shi Zhi-hui Li The Key Laboratory of Radiation Physics and Technology of Ministry of Education Institute of Nuclear Science and Technology Sichuan University

The proton beam with energy around 100 MeV has seen wide applications in modern scientific research and in various ***,proton sources in China fall short for meeting experimental needs owing to the vast size and expensive traditional proton *** Institute of Nuclear Science and Technology of Sichuan University proposed to build a 3 GHz side-coupled cavity linac(SCL)for re-accelerating a 26 MeV proton beam extracted from a CS-30 cyclotron to 120 *** carried out investigations into several vital factors of S-band SCL for proton acceleration,such as optimization of SCL cavity geometry,end cell tuning,and bridge coupler *** demonstrated that the effective shunt impedance per unit length ranged from 22.5 to 59.8 MX/m throughout the acceleration process,and the acceleration gradient changed from 11.5 to 15.7 MV/m when the maximum surface electric field was equivalent to Kilpatrick electric *** obtained equivalent circuit parameters of the biperiodic structures and applied them to the end cell tuning;results of the theoretical analysis agreed well with the 3D *** designed and optimized a bridge coupler based on the previously obtained biperiodic structure parameters,and the field distribution un-uniformness was\1.5%for a two-tank *** radio frequency power distribution system of the linac was obtained based on the preliminary beam dynamics design.

关键词： Proton beam Side-coupled cavity linac Accelerating cavity Biperiodic structure Bridge coupler