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^(15)N tracers and microbial analyses reveal in situ N_(2)O sources in contrasting water regimes of a drained peatland forest

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Pedosphere 2024年第4期34卷 749-758页

作者： Mohit MASTA Mikk ESPENBERG Laura KUUSEMETS Jaan PÄRN Sandeep THAYAMKOTTU Holar SEPP Kalle KIRSIMÄE Fotis SGOURIDIS Kuno KASAK Kaido SOOSAAR Ülo MANDER Institute of Ecology and Earth Sciences University of TartuVanemuise Street 46Tartu 51003Estonia School of Geographical Sciences University of BristolUniversity RoadBristol BS81SSUK

Managed peatlands are a significant source of nitrous oxide(N_(2)O),a powerful greenhouse gas and stratospheric ozone *** to the complexity and diversity of microbial N_(2)O processes,different methods such as tracer,isotopomer,and microbiological technologies are required to understand these *** combined application of different methods helps to precisely estimate these processes,which is crucial for the future management of drained peatlands,and to mitigate soil degradation and negative atmospheric *** this study,we investigated N_(2)O sources by combining tracer,isotopomer,and microbial analysis in a drained peatland forest under flooded and drained *** average,the nitrification genes showed higher abundances in the drained treatment,and the denitrification genes showed higher abundances in the flooded *** is consistent with the underlying chemistry,as nitrification requires oxygen while denitrification is *** observed significant differences in labelled N_(2)O fluxes between the drained and flooded *** emissions of N_(2)O from the flooded treatment were nearly negligible,whereas the N_(2)O evolved from the nitrogen-15(^(15)N)-labelled ammonium(^(15)NH4+)in the drained treatment peaked at 147μg ^(15)N m^(-2) h^(-1).This initially suggested nitrification as the driving mechanism behind N_(2)O fluxes in drained peatlands,but based on the genetic data,isotopic analysis,and N_(2)O mass enrichment,we conclude that hybrid N_(2)O formation involving ammonia oxidation was the main source of N_(2)O emissions in the drained *** on the ^(15)N-labelled nitrate(^(15)NO3-)tracer addition and gene copy numbers,the low N_(2)O emissions in the flooded treatment came possibly from complete denitrification producing inert *** atomic level,we observed selective enrichment of mass 45 of N_(2)O molecule under ^(15)NH4+amendment in the drained treatment and enrichment of both masses 45 and 46 under

关键词： denitrification nitrification N_(2)O quantitative polymerase chain reaction

Magmatic-tectonic response of the South China Craton to the Paleo-Pacific subduction during the Triassic:a new viewpoint based on Well NK-1

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Journal of Oceanology and Limnology 2024年第1期42卷 58-89页

作者： Chan WANG Hao LIU Gang LI Zhen SUN Tingting GONG Li MIAO Xiaowei ZHU Yunying ZHANG Weihai XU Wen YAN Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Key Laboratory of Tectonic Controlled Mineralization and Oil Reservoir of ministry of Natural Resources Chengdu University of TechnologyChengdu 610059China School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China College of Earth Science Chengdu University of TechnologyChengdu 610059China University of Chinese Academy of Sciences Beijing 100049China

The Nansha Block(NB)is one of the blocks separated from the southern margin of the South China Craton(SCC)by the western Pacific subduction,which contains rich information of geodynamic and tectonic *** reveal the essence of western Paleo-Pacific subduction during the Triassic period,Well NK-1 in this block was selected for petrographic study,and published research data from other cooperative teams were compared.A double-cycle pattern of basic to neutral magmatic volcanism was established,and 36 lithological rhythmic layers and representative cryptoexplosive breccia facies and welded tuff bands were *** with a reanalysis of published geochronological data,geochemical elements,and isotope geochemistry,we found that the rock assemblages could be divided into an intermediate-acid dacite(DA)series(SiO_(2)>65%)and basaltic(BA)series(Co<40μg/g),which was formed during the early Late Triassic((218.6±3.2)–(217.9±3.5)Ma).BA exhibits obvious calc-alkaline island-arc magmatic properties:(^(87)Sr/^(86)Sr)_i ratio ranging 0.70377–0.71118(average:0.70645),^(147)Sm/^(144)Nd ratio ranging 0.119–0.193(average:0.168),and chondrite-normalized rare earth element(REE)curves being flat,while DA exhibits remarkable characteristics of subducted island-arc andesitic magma:(^(87)Sr/^(86)Sr)_i ratio(0.70939–0.71129;average:0.71035),εNd(t)value(-6.2–-4.8;average:-5.6)andε_(Hf)(t)value(-2.9–-1.7,average:-2.2)show obvious crust-mantle mixing *** and DA reveal typical characteristics of island-arc magma systems and typeⅡenriched mantle(EM-Ⅱ)*** magma was likely resulted from the process whereby the continental crust frontal accretionary wedge was driven by the Paleo-Pacific slab subduction into the deep and began to melt,resulting in a large amount of melt(fluid)joined the asthenosphere on the side of the continental *** contrast,DA magma was likely resulted from the process whereby the plate front was forced to bend with increasing subducti

关键词： Paleo-Pacific tectonic domain tectonic evolution rift volcanic rock Nansha Block South China Craton

比较三种稳定剂对FeS纳米颗粒的稳定效果及对水土中镉的固定与去除性能的影响

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Journal of Central South University 2024年第4期31卷 1064-1075页

作者：田舒婷赵东叶霍丽娟马骏杨睿 Department of Environmental Science School of Environment and ResourcesTaiyuan University of Science and TechnologyTaiyuan 030024China Environmental Engineering Program Department of Civil&Environmental EngineeringAuburn UniversityAuburnAL 36849USA Department of Civil Constructionand Environmental EngineeringSan Diego State UniversitySan DiegoCA 92182USA

本研究评估了三种多糖稳定剂(羧甲基纤维素钠(CMC)、羧甲基淀粉钠(CMS)和一种水溶性淀粉)用于稳定FeS纳米颗粒的有效性,并测试了相应稳定化纳米颗粒在水和土壤中固定Cd^(2+)的性能。使用0.010 wt%CMC、0.025 wt%CMS或0.065 wt%淀粉可获... 详细信息

本研究评估了三种多糖稳定剂(羧甲基纤维素钠(CMC)、羧甲基淀粉钠(CMS)和一种水溶性淀粉)用于稳定FeS纳米颗粒的有效性,并测试了相应稳定化纳米颗粒在水和土壤中固定Cd^(2+)的性能。使用0.010 wt%CMC、0.025 wt%CMS或0.065 wt%淀粉可获得完全稳定的FeS纳米颗粒(100 mg/L FeS)。CMC-FeS表现出较高的zeta负电位,淀粉-FeS保持中性,而CMS-FeS则表现出中等负电位。CMCFeS对Cd^(2+)的吸附速率最快,吸附容量也最高。当用100 mg/L CMC-FeS或CMS-FeS处理一种含Cd土壤(58.3 mg/kg Cd)后,Cd的TCLP浸出率分别降低了88.4%和68.0%。CMC-FeS和CMS-FeS均可在模型土壤中运移,显示出其在土壤中原位固定Cd^(2+)方面的潜力。土壤穿透曲线实验表明,CMC-FeS在4.5个孔体积,CMS-FeS在约25个孔体积处几乎完全穿透。柱实验结果表明,当用55个孔体积的CMC-FeS或CMS-FeS悬浮液(100 mg/L)处理该含Cd土壤后,Cd的水浸出率分别降低了98.2%和98.0%。根据目标污染物、材料在土壤中的传输特性和材料成本,可找到这三种稳定剂在土壤修复中的最佳应用。

关键词：硫化铁纳米颗粒稳定剂重金属污染物固定土壤修复地下水污染

Design of high-temperature superconductors at moderate pressures by alloying AlH3 or GaH3

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Matter and Radiation at Extremes 2024年第1期9卷 94-103页

作者： Xiaowei Liang Xudong Wei Eva Zurek Aitor Bergara Peifang Li Guoying Gao Yongjun Tian Center for High Pressure Science(CHiPS) State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China School of Materials Science and Engineering Henan University of TechnologyZhengzhou 450001China Department of Chemistry State University of New York at BuffaloBuffaloNew York 14260-3000USA Physics Department and EHU Quantum Center University of the Basque CountryUPV/EHU48080 BilbaoSpain Donostia International Physics Center(DIPC) 20018 DonostiaSpain Centro de Física de Materiales CFM Centro Mixto CSIC-UPV/EHU20018 DonostiaSpain Extreme Conditions Physics Research Team College of Physics and Electronic InformationInner Mongolia Minzu UniversityTongliao 028043China

Since the discovery of hydride superconductors,a significant challenge has been to reduce the pressure required for their *** this context,we propose that alloying could be an effective strategy to achieve *** focus on a series of alloyed hydrides with the AMH_(6)composition,which can be made via alloying A15 AH_(3)(A=Al or Ga)with M(M=a group IIIB or IVB metal),and study their behavior under *** of them are predicted to maintain the A15-type structure,similar to AH_(3)under pressure,providing a platform for studying the effects of alloying on the stability and superconductivity of AH_(3).Among these,the A15-type phases of AlZrH_(6)and AlHfH_(6)are found to be thermodynamically stable in the pressure ranges of 40–150 and 30–181 GPa,***,they remain dynamically stable at even lower pressures,as low as 13 GPa for AlZrH_(6)and 6 GPa for AlHfH_(6).These pressures are significantly lower than that required for stabilizing A15 ***,the introduction of Zr or Hf increases the electronic density of states at the Fermi level compared with *** enhancement leads to higher critical temperatures(Tc)of 75 and 76 K for AlZrH_(6)and AlHfH_(6)at 20 and 10 GPa,*** the case of GaMH_(6)alloys,where M represents Sc,Ti,Zr,or Hf,these metals reinforce the stability of the A15-type structure and reduce the lowest thermodynamically stable pressure for GaH_(3) from 160 GPa to 116,95,80,and 85 GPa,*** noteworthy are the A15-type GaMH_(6)alloys,which remain dynamically stable at low pressures of 97,28,5,and 6 GPa,simultaneously exhibiting high Tc of 88,39,70,and 49 K at 100,35,10,and 10 GPa,***,these findings enrich the family of A15-type superconductors and provide insights for the future exploration of high-temperature hydride superconductors that can be stabilized at lower pressures.

关键词： alloying alloys superconductors

Therapeutic and Immunoregulatory Effect of GATA-Binding Protein-3/T-Box Expressed in T-Cells Ratio of Astragalus Polysaccharides on 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis in Rats

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Chinese Journal of Integrative Medicine 2016年第12期22卷 918-924页

作者：高永健朱峰钱家鸣戴佳原 department of gastroenterology peking union medical college hospitalchinese academy of medical sciences and peking union medical collegeBeijing 100071China

Objective： To analyze the immunological characteristics of 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced colitis model and examine the therapeutic effects and mechanisms of Astragalus polysaccharides（APS） treatment. Methods： Thirty-two male specific pathogen free Spragne-Dawley rats were randomly equally assigned to four groups： control, TNBS, APS and prednisone groups. Experimental colitis was induced by enema administration of TNBS. Then rats were treated with APS（0.5 g·kg^（-1）·day^（-1）, once daily） or prednisone（1.0 mg·kg^（-1）·day^（-1）, once daily） by gavage for 14 days. Macroscopic lesion and histological damage were determined, and activity of myeloperoxidase（MPO） was measured in the colonic tissues. Expressions of T-box expressed in T-cells（T-bet） and GATA-binding protein-3（GATA-3） were determined by immunohistochemistry analysis and western blot. Results： Both macroscopic lesion and histological colonic damage induced by TNBS were reduced by APS and prednisone treatment. These were accompanied by significant attenuation of MPO activity（P=0.03）. TNBS intervention enhanced the expression of both GATA-3 and T-bet, but the expression of T-bet was significantly enhanced than that of GATA-3, resulting in significant reduction of GATA-3/T-bet ratio（P=0.025）. APS administration enhanced the expression of T-bet（P=0.04） and GATA-3（P=0.019） in comparison to TNBS group, and resulting in an up-regulated GATA-3/T-bet ratio. Prednisone treatment inhibited both expressions; however it also resulted in up-regulation of the GATA-3/T-bet ratio. Conclusions： These results demonstrated that APS exerted a beneficial immune regulatory effect on experimental colitis. It promoted the expression of T helper cell 1（Th1） and T helper cell 2（Th2） specific transcription factors but ultimately favor a shift toward Th2 phenotype, suggesting that APS possessed therapeutic potential in experimental colitis.

关键词： Astragalus polysaccharides 2 4 6-trinitrobenzene sulfonic acid-induced colitis rats T-bet GATA-3 Chinese medicine

DYNAMICS FOR A CHEMOTAXIS MODEL WITH GENERAL LOGISTIC DAMPING AND SIGNAL DEPENDENT MOTILITY

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Acta Mathematica Scientia 2024年第3期44卷 1046-1063页

作者：涂馨予穆春来邱蜀燕张静 School of Mathematics and Statistics Southwest UniversityChongqing400715China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHung HomHong KongChina College of Mathematics and Statistics Chongqing UniversityChongqing401331China School of Sciences Southwest Petroleum UniversityChengdu610500China

In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥1)is a smooth and bounded domain,λ≥0,μ≥0,κ>1,and the motility function satisfies thatγ(v)∈C3([0,∞)),γ(v)>0,γ′(v)≤0 for all v≥*** the Neumann boundary condition,we obtain the global boundedness of solutions if one of the following conditions holds:(i)λ=μ=0,1≤nλ3;(ii)λ>0,μ>0,combined withκ>1,1≤n≤3 or k>n+2/4,,n>***,we prove that the solution (u, v, w, z) exponentially converges to the constant steady state ((λ/μ)1/k-1,∫Ωv0dx+∫Ωw0dx/|Ω|,0,(λ/μ)1/k-1).

关键词： chemotaxis signal-dependent motility logistic source boundedness asymptotic behavior

The Arabidopsis phosphatase PP2C49 negatively regulates salt tolerance through inhibition of At HKT1;1

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Journal of Integrative Plant Biology 2021年第3期63卷 528-542页

作者： Moli Chu Pengwang Chen Sufang Meng Peng Xu Wenzhi Lan State Key Laboratory for Pharmaceutical Biotechnology School of Life SciencesNanjing UniversityNanjing 210023China

Type 2C protein phosphatases(PP2Cs)are the largest protein phosphatase ***2Cs dephosphorylate substrates for signaling in Arabidopsis,but the functions of most PP2 Cs remain ***,we characterized PP2 C49(AT3G62260,a Group G PP2C),which regulates Na^(+)distribution under salt stress and is localized to the cytoplasm and ***2C49 was highly expressed in root vascular tissues and its disruption enhanced plant tolerance to salt *** with wild type,the pp2c49 mutant contained more Na^(+)in roots but less Na^(+)in shoots and xylem sap,suggesting that PP2C49 regulates shoot Na^(+)*** grafting revealed a root-based mechanism underlying the salt tolerance of pp2 *** Na+distribution largely depends on AtHKT1;1 and loss of function of AtHKT1;1 in the pp2c49 background overrode the salt tolerance of pp2c49,resulting in salt ***,compared with plants overexpressing PP2C49 in the wild-type background,plants overexpressing PP2C49 in the athtk1;1 mutant background were sensitive to salt,like the athtk1;1 ***,protein-protein interaction and two-voltage clamping assays demonstrated that PP2C49 physically interacts with AtHKT1;1 and inhibits the Na^(+)permeability of AtHKT1;*** study reveals that PP2C49 negatively regulates AtHKT1;1 activity and thus determines systemic Na^(+)allocation during salt stress.

关键词： Arabidopsis At HKT1,1 Na+distribution translocation PP2C PP2C49 salt stress

Synthesis, characterization, crystal structure and antitumor activities of a novel demethylcantharidato bridged copper(Ⅱ) phenanthroline complex

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Science China Chemistry 2013年第4期56卷 481-489页

作者： YIN FuLing ZHU JingJing HAO Jian CUI JingRong YANG JunJiao Department of Chemical Biology School of Pharmaceutical Sciences Peking University Institutes for Advanced Interdisciplinary Research East China Normal University State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology State Key Laboratory of Natural and Biomimetic Drugs Peking University Health Science Center

A new polymeric demethylcantharidato （DCA） bridged copper（II） phenanthroline （phen） complex （[Cu（DCA）（phen）]n-nH20） has been synthesized and characterized by elemental analysis, IR and electronic spectra studies, molar conductivity measure- ment, and single crystal X-ray diffraction. The complex crystallizes in the orthorhombic space group Pbca with crystallo- graphic data： a -- 12.4537（4）/~, b = 9.3897（5） A, c = 30.1264（10） A, and Z = 8. In the crystal structure, the octahedral coordi- nated copper（II） ions are bridged by demethylcantharidate ligands into a one-dimensional zigzag-like structure with the Cu＇＂Cu separation of 6.1719/~, along with phen ligands attached to both sides of the chain altematively. Interdigitation of the chelating phen ligands of two neighboring chains via hydrophobic interaction and van der Waals forces along ac plane forms two-dimensional polymeric bilayers with discrete water sandwich layer between the adjacent polymeric bilayers. The evalua- tion of the cytotoxic activity of the copper（II） complex against HCT-8 （colorectal carcinoma）, A549 （pulmonary carcinoma）, HeLa （cervical cancer）, HepG2 （hepatocarcinoma）, BGC-823 （gastric carcinoma）, and MCF-7 （breast adenocarcinoma） cell lines revealed that it is a potent cytotoxic agent, superior to Na2DCA and phen against HeLa, HepG2 and BGC-823 cells.

关键词： demethylcantharidato-bridge polymeric copper(II) complex crystal structure cytotoxic activity

Efficient design of rotary traveling wave oscillator array via geometric programming

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第12期10卷 1815-1823页

作者： Li-jia CHEN Hua-feng ZHANG Jin-fang ZHOU Kang-sheng CHEN Department o fin formation Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

This paper presents an efficient method for globally optimizing and automating component sizing for rotary traveling wave oscillator arrays. The lumped equivalent model of transmission lines loaded by inverter pairs is evaluated and posynomial functions for oscillation frequency, power dissipation, phase noise, etc. are formulated using transmission line theory. The re- sulting design problem can be posed as a geometric programJning problem, which can be efficiently solved with a convex opti- mization solver. The proposed method can compute the global optima more efficiently than the traditional iterative scheme and various design problems can be solved with the same circuit model. The globally optimal trade-off curves between competing objectives are also computed to carry out robust designs and quickly explore the design space.

关键词： Rotary traveling wave oscillator array (RTWOA) Clock distribution Transmission line resonator Global optimi-zation Geometric programming (GP)