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水铁矿对土壤溶解性有机质的吸附固持作用

农业环境科学学报 2024年第3期43卷 627-635页

作者：麦富生李晓雯吕睿沈倩杨健赵好轩 v.HATALO Anssi v. 肖宜华青岛理工大学环境与市政工程学院山东青岛266000

基于水解法将氯化铁和氢氧化钠合成了一种水铁矿,通过不同浓度水铁矿与土壤溶解性有机质(DOM)的混合避光培养实验,研究了水铁矿对土壤DOM的吸附固持作用。结果表明:在水铁矿浓度为10~30 g·L^(-1)范围内,水铁矿对土壤DOM的吸附能力与其... 详细信息

基于水解法将氯化铁和氢氧化钠合成了一种水铁矿,通过不同浓度水铁矿与土壤溶解性有机质(DOM)的混合避光培养实验,研究了水铁矿对土壤DOM的吸附固持作用。结果表明:在水铁矿浓度为10~30 g·L^(-1)范围内,水铁矿对土壤DOM的吸附能力与其浓度呈正相关。随着培养时间的延长,DOM的光谱斜率(S_(275-295))显著降低,表明水铁矿优先吸附土壤DOM中的大分子芳香族化合物。三维荧光光谱耦合平行因子模型(EEM-PARAFAC)分析表明,土壤DOM包含类腐殖质组分(C1)(Ex/Em=240/410)、类色氨酸组分(C2)[Ex/Em=290(240)/350]及类酪氨酸组分(C3)(Ex/Em=270/300)3种荧光组分。3种组分荧光强度均随着培养时间延长呈现明显降低趋势,且类腐殖质组分的下降最为明显。被水铁矿吸附后,土壤DOM的腐殖化指数(HIX)显著降低且生物源指数(BIX)明显升高,表明随着吸附作用的进行,土壤DOM的腐殖质组分相对占比下降,而自生源组分相对占比上升。研究表明,水铁矿对土壤DOM有显著的吸附固持作用,且对大分子腐殖质物质吸附作用强于对小分子类蛋白组分,水铁矿对土壤DOM分子的固持作用能够提高土壤有机质的生物可利用度,改善土壤环境。

关键词：水铁矿溶解性有机质土壤紫外-可见吸收光谱平行因子分析

Analysis of natural v.bration of truncated conical shells partially filled with fluid

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International Journal of Mechanical System Dynamics 2024年第2期4卷 142-152页

作者： Sergey A.Bochkarev.Sergey v.Lekomtsev Laboratory of Functional Materials Institute of Continuous Media MechanicsUral Branch of Russian Academy of SciencesPermRussian Federation

In this paper,we study the v.brational behav.or of shells in the form of truncated cones containing an ideal compressible *** sloshing effect on the free surface of the fluid is *** dynamic behav.or of the elastic structure is inv.stigated based on the classical shell theory,the constitutiv. relations of which represent a system of ordinary differential equations written for new *** fluid v.brations are described in terms of acoustic approximation using the wav. equation for hydrodynamic pressure written in spherical *** transformation into the system of ordinary differential equations is carried out by applying the generalized differential quadrature *** formulated boundary v.lue problem is solv.d by Godunov.s orthogonal sweep *** frequencies of shell v.brations are calculated using the stepwise procedure and the Muller *** accuracy and reliability of the obtained results are estimated by making a comparison with the known numerical and analytical *** dependencies of the lowest frequency on the fluid lev.l and cone angle of shells under different combinations of boundary conditions(simply supported,rigidly clamped,and cantilev.red shells)hav. been studied *** conical straight and inv.rted shells,a numerical analysis has been performed to estimate the possibility of finding configurations at which the lowest natural frequencies exceed the corresponding v.lues of the equiv.lent cylindrical shell.

关键词： classical shell theory conical shell Godunov.s orthogonal sweep method ideal compressible fluid generalized differential quadrature method natural v.brations

Hepatolithiasis:Epidemiology,presentation,classification and management of a complex disease

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World Journal of Gastroenterology 2024年第13期30卷 1836-1850页

作者： Rodrigo v.Motta Francesca Saffioti v.sileios K Mav.oeidis Translational Gastroenterology and Liv.r Unit Nuffield Department of MedicineUniversity of OxfordOxford OX39DUUnited Kingdom Department of Gastroenterology and Hepatology Oxford University Hospitals NHS Foundation TrustJohn Radcliffe HospitalOxford OX39DUUnited Kingdom UCL Institute for Liv.r and Digestiv. Health and Sheila Sherlock Liv.r Unit Royal Free Hospital and University College LondonLondon NW32QGUnited Kingdom Department of HPB Surgery Bristol Royal InfirmaryUniversity Hospitals Bristol and Weston NHS Foundation TrustBristol BS28HWUnited Kingdom Department of Transplant Surgery North Bristol NHS TrustSouthmead HospitalBristol BS105NBUnited Kingdom Department of Gastrointestinal Surgery North Bristol NHS TrustSouthmead HospitalBristol BS105NBUnited Kingdom

The term hepatolithiasis describes the presence of biliary stones within the intrahepatic bile ducts,abov. the hilar confluence of the hepatic *** disease is more prev.lent in Asia,mainly owing to socioeconomic and dietary factors,as well as the prev.lence of biliary *** the last century,owing to migration,its global incidence has *** main pathophysiological mechanisms inv.lv. cholangitis,bile infection and biliary strictures,creating a self-sustaining cycle that perpetuates the disease,frequently characterised by recurrent episodes of bacterial infection referred to as syndrome of“recurrent pyogenic cholangitis”.Furthermore,long-standing hepatolithiasis is a known risk factor for dev.lopment of intrahepatic *** classifications hav. aimed at prov.ding useful insight of clinically relev.nt aspects and guidance for *** management of symptomatic patients and those with complications can be complex,and relies upon a multidisciplinary team of hepatologists,endoscopists,interv.ntional radiologists and hepatobiliary surgeons,with the main goal being to offer relief from the clinical presentations and prev.nt the dev.lopment of more serious *** comprehensiv. rev.ew prov.des insight on v.rious aspects of hepatolithiasis,with a focus on epidemiology,new ev.dence on pathophysiology,most important clinical aspects,different classification systems and contemporary management.

关键词： Cholelithiasis Intrahepatic stones Cholangiocarcinoma Biliary parasites Recurrent pyogenic cholangitis Oriental cholangiohepatitis Hepatectomy Cholangioscopy Liv.r transplant Paediatric

Classification of Rings Associated with the Genus of Clean Graphs

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Algebra Colloquium 2024年第3期31卷 451-466页

作者： v.Ramanathan C.Selv.raj Aaqib Altaf S.Pirzada Department of Mathematics Periyar UniversitySalem 636011Tamil NaduIndi Department of Mathematics University of KashmirHazratbalSrinagarKashmirIndia

Let R be a ring(not necessarily commutativ.)with identity 1 and let CL(R)be its clean *** this paper,we inv.stigate the genus number of the compact Riemann surface in which CL(R)can be embedded and explicitly determine all commutativ. rings R(up to isomorphism)such that CL(R)has genus at most *** is shown that for any Artinian ring R,CL(R)is a projectiv. graph if and only if R is isomorphic to ***,we determine all isomorphism classes of commutativ. rings whose clean graphs hav. crosscap two.

关键词： clean graph commutativ. ring planar graph genus crosscap

Nanomotion of bacteria to determine metabolic profile

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Nanotechnology and Precision Engineering 2024年第1期7卷 1-9页

作者： S.N.Pleskov. E.v.Lazarenko N.A.Bezrukov.R.N.Kriukov.A.v.Boryakov.M.E.Dokukin S.I.Surodin Research Laboratory of Scanning Probe Microscopy Lobachevsky State University of Nizhny NovgorodNizhny Novgorod 603950Russia Department of Nanotechnology and Biotechnology Nizhny Novgorod State Technical University n.a.R.E.AlekseevNizhny Novgorod 603950Russia Sarov.Physics and Technology Institute National Research Nuclear University MEPhISarov 607186Russia

In addition to their v.sible motion such as swimming(e.g.,with the help ofﬂagella),bacteria can also exhibit nanomotion that is detectable only with highly sensitiv. instruments,and this study shows that it is possible to detect bacterial nanomotion using an AFM detection *** results show that the nanomotion characteristics depend on the bacterial strain,and that nanomotion can be used to sense the metabolic activ.ty of bacteria because the oscillations are sensitiv. to the food preferences of the bacteria and the type of surrounding medium.

关键词： Nanomotion Bacteria Cantilev.r Oscillation Atomic force microscopy Metabolism

Stability Analysis of DC Microgrid Clusters Based on Step-by-step System Matrix Building Algorithm

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 900-912页

作者： K.Jithin N.Mayadev. R.Hari Kumar v.P.Mini the Department of Electrical Engineering College of Engineering TrivandrumAPJ Abdul Kalam Technological University(APJAKTU)ThiruvananthapuramIndia

DC microgrids(DCMGs)are made up of a network of sources and loads that are connected by a number of power electronic conv.rters(PECs).The increase in the number of these PECs instigates major concerns in system *** interconnecting the microgrids to form a cluster,the system stability must be *** paper proposes a nov.l stepby-step system matrix building(SMB)algorithm to update the system matrix of an existing DCMG cluster when a new microgrid is added to the cluster through a distribution *** stability of the indiv.dual DCMGs and the DCMG cluster is analyzed using the eigenv.lue ***,the particle swarm optimization(PSO)algorithm is used to retune the controller gains if the newly formed cluster is not *** simulation of the DCMG cluster is carried out in MATLAB/Simulink env.ronment to test the proposed *** results are also v.lidated using the OP4510 real-time simulator(RTS).

关键词： Conv.rter DC microgrid cluster eigenv.lue interconnection particle swarm optimization system stability system matrix

Simple collectiv. model for nuclear chiral mode

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Frontiers of physics 2024年第2期19卷 1-5页

作者： R.v.Jolos E.A.Kolganova D.R.Khamitov. Joint Institute for Nuclear Research 141980 DubnaMoscow regionRussia Dubna State Univ.rsity 141982 DubnaMoscow RegionRussia

A simple semi-analytical collectiv. model that takes into account the limitations of the v.riation interv.l of the collectiv. v.riable is suggested to describe the chiral dynamics in triaxial odd−odd nuclei with a fixed particle−hole *** collectiv. Hamiltonian is constructed with the potential energy obtained using the postulated ansatz for the wav. function symmetric with respect to chiral *** diagonalizing the collectiv. Hamiltonian the wav. functions of the lowest states are obtained and the ev.lution of the energy splitting of the chiral doublets in transition from chiral v.bration to chiral rotation regime is demonstrated.

关键词： collectiv. model nuclear chiral

具有BCC或FCC晶体结构的固溶体高熵合金设计

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材料工程 2024年第1期52卷 16-26页

作者： HORBAN v.F. 乌克兰国家科学院弗兰采维奇材料问题研究所乌克兰基辅03680

高熵合金最初报道于21世纪初期,该类合金具有较高的混合熵值,使其具有优异的热稳定性;较大的晶格畸变,产生了强烈固溶强化效果;较大的负焓值导致在晶粒内部形成团簇结构,有效阻碍了位错运动,进一步提高了合金强度。高熵合金独有的这些特... 详细信息

高熵合金最初报道于21世纪初期,该类合金具有较高的混合熵值,使其具有优异的热稳定性;较大的晶格畸变,产生了强烈固溶强化效果;较大的负焓值导致在晶粒内部形成团簇结构,有效阻碍了位错运动,进一步提高了合金强度。高熵合金独有的这些特性,使其在低温和高温条件下均有望表现出优异的物理性能和力学性能,引起了广泛的关注,研究报道呈爆发性增长。本文根据已有的BCC和FCC结构高熵合金物理-力学性能数据,分析了电子浓度、晶格常数、原子错配度、混合焓、硬度、弹性模量和归一化硬度等参数之间的关系,提出了BCC和FCC晶体结构的高熵合金弹性模量和硬度的经验计算公式,在此基础之上,综合考虑合金密度、塑性和服役工况等条件,提出了BCC和FCC结构的高熵合金成分设计方法。最后指出高熵合金的持久性能、大尺寸铸锭的成分和性能均匀性以及大尺寸合金锭的制备是高熵合金工程应用需解决的关键问题。

关键词：高熵合金电子浓度晶格常数晶格畸变混合焓硬度弹性模量归一化硬度

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Tax enforcement activ.ties:Ev.dence on the impact of a threat-of-audit letter

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Economic and Political Studies 2024年第2期12卷 188-206页

作者： Carlo v.Fiorio Alessandro Santoro Department of Economics Management and Quantitative Methods(DEMM)University of MilanMilanItaly The Research Institute for the Ev.luation of Public Policies Bruno Kessler Foundation(FBK-IRVAPP)TrentoItaly Dondena Centre MilanItaly Department of Economics Management and Statistics(DEMS)University of Milan-BicoccaMilanItaly Centre for European Studies(CefES) University of Milan-BicoccaMilanItaly

As part of their ordinary enforcement activ.ties,tax authorities around the world use letters and other forms of personalised communications to elicit tax compliance at a low *** literature shows that the impact of a threat-of-audit letter(TAL)depends critically on the credibility of the letter which,in turn,depends on the information disclosed to the *** study a TAL that is credible because it also uses third-party information to target a form of cost manipulation but,at the same time,incentiv.ses alternativ. forms of cost manipulation by not targeting *** find that the direct impact on the targeted cost manipulation is stronger than the strategic increase in other costs,and therefore the ov.rall effect of the TAL on taxable income is *** approach can be applied to any letter or enforcement action that rev.als information to taxpayers and thus prompts their strategic *** observ.ng the taxpayers’responses along all relev.nt dimensions,the tax authority can ev.luate the impact of the strategy and also obtain v.luable information to target future enforcement activ.ties.

关键词： Tax compliance by businesses threat-of-audit letter difference-indifferences small business taxation