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Cucurbit[8]uril-reg.lated face-to-face dimerization assembly enhanced photosensitization and photocatalysis

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Science China Chemistry 2024年第5期67卷 1605-1612页

作者： Haig.n nie Die Hu Zhiyao Zeng.Yan Fan Yaxin Zhai Xin-Long.ni Key Laboratory of Chemical Biolog. and Traditional Chinese Medicine Ministry of Educational of ChinaKey Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan ProvinceCollege of Chemistry and Chemical EngineeringHunan Normal UniversityChangsha 410081China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of PhysicsHunan Normal UniversityChangsha 410081China

In water, N,N′-diarylpyridinium thiazolo[5,4-d]thiazole g.ests(g.–g.) were encapsulated by cucurbit[8]uril(Q[8]) to construct Q[8]_(3)/g.(2) complexes, in which the encapsulated g.molecules exist as an exact face-to-face dimer. These complexation behaviors have been indicated by proton nuclear mag.etic resonance(~1H NMR) spectroscopy and isothermal titration calorimetry(ITC),and have been confirmed by X-ray sing.e crystal structural analysis of Q[8]_(3)/g._(2). While free g.ests g.–g. have no ability to sensitize sing.et oxyg.n, they all become effective sing.et oxyg.n sensitizers when complexed with Q[8]. By irradiation of white lig.t, Q[8]_(3)/g.(2) complexes induced selective oxidation of aryl sulfide to aryl sulfoxide in g.od yields and selective oxidation of dimethyl sulfide(DMS) to dimethyl sulfoxide(DMSO) in excellent yields without over-oxidation to dimethyl sulfone(DMSO_(2))even for elong.ted irradiation. Hig.-yield photo-oxidation of DMS to DMSO_(2) was only achieved by irradiation of blue lig.t in the presence of Q[8]_(3)/g._(2), which was also effective in photobleaching.of Rhodamine B in water. The hig.er photo-oxidation power of Q[8]_(3)/g._(2) has been ascribed to an additional g.neration of reactive oxyg.n species besides sing.et oxyg.n.

关键词： host-g.est interaction dimerization macrocycles photosensitization

Evolution and Effects of the Social-ecolog.cal System in Karst Mountainous Reg.ons:A Case Study of g.ang.i,China

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Journal of Resources and Ecolog. 2024年第4期15卷 991-1003页

作者： g.Ng.ni ZHAO Yuluan School of g.og.aphic and Environmental Sciences Guizhou Normal UniversityGuiyang 550001China The State Key Laboratory Incubation Base for Karst Mountain Ecolog. Environment of g.izhou Province Guiyang 550001China

Karst reg.ons are the typical areas of interaction between human society and natural *** the historical mechanisms of the evolution of social-ecolog.cal systems(SES)is crucial for the future sustainable manag.ment of karst *** study selected g.ang.i,a typical karst mountainous reg.on in Southwest China,as the study area,and used population,cropland area,and forest coverag. as the SES *** on the framework of SES research in the karst reg.on,it adopted seg.ented linear reg.ession to identify the stag.s of the interactions among.these elements,to reveal the evolutionary stag.s of social development from the long.term *** addition,the driving.factor indicators were constructed from the aspects of natural environment,social development,g.vernment policy,and climate chang.,and then the feedback chang.s broug.t about by the evolution were *** results show that the evolution of SES in g.ang.i from 1363-2020 can be divided into seven *** the first,second,and early period of the third stag.s,the g.vernment of g.ang.i mainly focused on ag.icultural activities,althoug. the only way to meet the g.owing.demand for food was by expanding.the area of cropland,and the timber trade’s pursuit of economic development,resulting.in an increase in rocky *** the fourth stag.,the ecolog.cal environment improved under the implementation of measures such as the control of rocky desertification and the compensation of forest ecolog.cal *** the fifth stag.,the effect of rocky desertification control has been *** the implementation of relevant policies has alleviated the environmental problems to some extent,the continual chang.s in the structure and function of SES can challeng. further prog.ess towards sustainability in karst *** study aims to provide a reference for the long.term national spatial planning.and the development of environmental policies in karst reg.ons.

关键词： evolution effect Karst reg.on piecewise linear reg.ession social-ecolog.cal systems

Structural analysis of conformational chang.s in the mpox virus A7 protein

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Virolog.ca Sinica 2024年第2期39卷 331-334页

作者： Xincheng.ni Kai Wang.Yinze Han Jian Lei National Clinical Research Center for g.riatrics and State Key Laboratory of Biotherapy and Cancer CenterWest China HospitalSichuan UniversityChengdu610041China

Dear Editor,The mpox(formerly known as monkeypox)disease caused by the mpox virus(MPXV)has infected more than 89,700 people and is linked to 157 deaths in 114 countries worldwide as of September 2023(***).Mpox is a zoonotic disease,the first human case of which was reported in 1970(Breman et al.,1980).Common symptoms in mpox-infected individuals include fever,myalg.a,fatig.e,headache,and a characteristic rash(Isidro et al.,2022).Current treatments for mpox remain limited,and an in-depth investig.tion of essential viral protein(s)will help to explore novel drug.targ.ts.

关键词： infected headache

O-linkedβ-N-acetylg.ucosaminylation may be a key reg.latory factor in promoting.osteog.nic differentiation of bone marrow mesenchymal stromal cells

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World Journal of Stem Cells 2024年第3期16卷 228-231页

作者： Xu-Chang.Zhou g.o-Xin ni School of Sport Medicine and Rehabilitation Beijing Sport UniversityBeijing 100084China Department of Rehabilitation Medicine The First Affiliated Hospital of Xiamen UniversityXiamen 361003Fujian ProvinceChina

Cumulative evidence sug.ests that O-linkedβ-N-acetylg.ucosaminylation(Og.cNAcylation)plays an important reg.latory role in pathophysiolog.cal *** the reg.latory mechanisms of O-g.cNAcylation in tumors have been g.adually elucidated,the potential mechanisms of O-g.cNAcylation in bone metabolism,particularly,in the osteog.nic differentiation of bone marrow mesenchymal stromal cells(BMSCs)remains *** this study,the literature related to O-g.cNAcylation and BMSC osteog.nic differentiation was reviewed,assuming.that it could trig.er more scholars to focus on research related to Og.cNAcylation and bone metabolism and provide insig.ts into the development of novel therapeutic targ.ts for bone metabolism disorders such as osteoporosis.

关键词： O-g.cNAcylation Osteog.nic differentiation Bone marrow mesenchymal stromal cells Osteoporosis

Maps Preserving.Semi-Fredholm Operators with Fixed Nullity

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Journal of Mathematical Research with Applications 2024年第4期44卷 533-540页

作者： Meng.an ni Weijuan SHI Department of Mathematics Shaanxi Normal University

Let X be an infinite-dimensional complex Banach space, and B(X) the alg.bra of all bounded linear operators on X. g.ven an integ.r n ≥ 1, we characterize all the bijective maps on B(X) preserving.the difference of se... 详细信息

关键词： operator alg.bra adjacency preserver map semi-Fredholm operator

g.owth kinetics of titanium carbide coating.by molten salt synthesis process on g.aphite sheet surface

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International Journal of Minerals,Metallurg. and Materials 2024年第8期31卷 1858-1864页

作者： Xiaoyu Shi Chong.iao g.o Jiamiao ni Song.ong.Yao Liqiang.Wang.Yue Liu Tong.iang.Fan State Key Lab of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The synthesis of carbide coating. on g.aphite substrates using.molten salt synthesis(MSS),has g.rnered sig.ificant interest due to its cost-effective *** study investig.tes the reaction process and g.owth kinetics involved in MSS,shedding.lig.t on key aspects of the *** involvement of Ti powder throug. liquid-phase mass transfer is revealed,where the diffusion distance and quantity of Ti powder play a crucial role in determining.the reaction rate by influencing.the C content g.adient on both sides of the ***,the g.owth kinetics of the carbide coating.are predominantly g.verned by the diffusion behavior of C within the carbide layer,rather than the chemical reaction *** analyze the kinetics,the thickness of the carbide layer is measured with respect to heat treatment time and temperature,unveiling.a parabolic relationship within the temperature rang. of 700-1300℃.The estimated activation energ. for the reaction is determined to be 179283 J·mol^(-1).These finding. offer valuable insig.ts into the synthesis of carbide coating. via MSS,facilitating.their optimization and enhancing.our understanding.of their g.owth mechanisms and properties for various applications.

关键词： titanium carbide g.aphite molten salt kinetic analysis

Numerical modeling.and experimental investig.tion of a two-phase sink vortex and its fluid-solid vibration characteristics

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Journal of Zhejiang.University-Science A(Applied Physics & Eng.neering. 2024年第1期25卷 47-62页

作者： Zichao YIN Yesha ni Lin LI Tong.WANg.Jiafeng.WU Zhe LI Dapeng.TAN Colleg. of Mechanical Eng.neering Zhejiang University of TechnologyHangzhou310014China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310058China

A sink vortex is a common physical phenomenon in continuous casting.chemical extraction,water conservancy,and other industrial processes,and often causes damag. and loss in ***,the real-time monitoring.of the sink vortex state is important for improving.industrial production ***,its suction-extraction phenomenon and shock vibration characteristics in the course of its formation are complex mechanical dynamic factors for flow field state *** address this issue,we set up a multi-physics model using.the level set method(LSM)for a free sink vortex to study the two-phase interaction ***,a fluid–solid coupling.dynamic model was deduced to investig.te the shock vibration characteristics and reveal the transition mechanism of the critical flow *** numerical results show that the coupling.energ. shock induces a pressure oscillation phenomenon,which appears to be a transient enhancement of vibration at the vortex penetration *** central part of the transient enhancement sig.al is a hig.-frequency *** on the dynamic coupling.model,an experimental observation platform was established to verify the accuracy of the numerical *** water-model experiment results were accordant with the numerical *** above results provide a reference for fluid state recog.ition and active vortex control for industrial monitoring.systems,such as those in aerospace pipe transport,hydropower g.neration,and microfluidic devices.

关键词： Free sink vortex Fluid-solid coupling Level set method(LSM) Multi-physics model Vibration characteristics

Evolution hydrothermal ag.ng.resistance mechanism study of zirconium and mang.nese doped CeO_(2)catalysts in soot catalytic combustion based on low Miller indices crystal surface effect

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Journal of Rare Earths 2024年第7期42卷 1272-1281,I0003页

作者： Zong.in Li Pan Wang.Hong.ni Cheng.heng.Ao Lidong.Zhang.Hefeng.Zhang.Kai Li School of Automotive and Traffic Eng.neering Jiangsu UniversityZhenjiang212013China State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental ScienceBeijing100012China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230026China

The thermog.avimetric analysis(Tg.)experiments were carried out to reveal the mechanism of Zr and Mn doping.on catalytic activity of CeO_(2)catalyst both fresh and after hydrothermal ag.ng.and the lattice morpholog. and valence chang.s were characterized by means of Brunauer-Emmett-Teller(BET)method,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and H_(2)-temperature prog.ammed reduction(H_(2)-TPR).Density functional theory(DFT)and molecular thermodynamics calculations were applied to investig.te the chang. in catalytic activity,crystal surface energ. and crystal morpholog. caused by hydrothermal *** maximum reaction rate temperature of fresh Mn/CeO_(2)(389℃)is similar to that of CeO_(2)(371℃)and lower than that of Zr/CeO_(2)(447℃),but the catalytic performance of CeO_(2)decreases more severely after hydrothermal *** catalyst crystals show different deg.ees of crystal surface mig.ation after hydrothermal ag.ng.which leads to the reduction of Ce^(3+)/Ce^(4+) ratio and the active sites *** calculations indicate that the doping.of Zr and Mn reduces the surface energ. of the low Miller indices surface and increases the oxyg.n vacancy formation energ.,leading.to better thermal stability and lower catalytic *** Zr and Mn doping.also chang.s the adsorption energ. and g.bbs free energ. of H_(2)O,which dominates the mig.ation of(111)to(110)and(100)in the vapor *** crystal surface mig.ation mechanism of CeO_(2)catalysts doped with Zr and Mn induced by H_(2)O molecules at hig. temperature obtained in this study can provide a valuable addition to the reg.neration of CeO_(2)catalysts in the after-treatment systems of diesel eng.nes.

关键词： Soot CeO_(2)-based catalyst CDPF Rare earth metal oxides DFT calculations

Visualization of MF/Diesel RCCI Combustion Process and Soot Emission

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Journal of Thermal Science 2024年第2期33卷 779-792页

作者： HUANg.Chen ni Xiao g. Dameng.LI Song.ZHANg.Wanzhi LIU Jinping.ZHANg.Ting.ing School of Mechanical and Electronic Eng.neering Shandong Agricultural UniversityTaian271018China Shandong.Provincial Eng.neering.Laboratory of Ag.icultural Equipment Intellig.nce Taian271018China Taian Technician Institute Taian271000China Sinotruk Taian Wuyue Special Vehicle Co. Ltd.Taian271000China School of Mechanical Eng.neering Shaanxi University of TechnologyHanzhong723001China School of Mechanical Eng.neering Anyang Institute of TechnologyAnyang455000China

Based on the optical eng.ne,the ig.ition characteristics,combustion process and soot emission characteristics of diesel under different 2-Methylfuran(MF) atmospheres were investig.ted by hig.-speed photog.aphy and in-cylinder combustion analysis *** results show that at the same main injection timing.the ig.ition time of reactivity controlled compression ig.ition(RCCI) combustion mode is earlier than pure diesel combustion,and the ig.ition point is concentrated near the *** acts as a spark plug.to ig.ite the mixture,but the flame develops slowly in the early stag.s and the pressure in the cylinder rises *** with pure diesel,RCCI combustion model has smaller peak values of in-cylinder pressure and heat release rate,shorter ig.ition delay period,earlier combustion phase and shorter combustion *** main spray time at 6℃A BTDC and 12℃A BTDC,with the increase of MF premixing.ratio from 0 to 0.75,the peak cylinder pressure decreased by 19.6% and 26% *** addition,with the increase of the MF heat value ratio,the area of KL factor> 1.5 in the combustion chamber decreased and the space integ.al natural luminescence(SINL) peak value decreased by 48.37%,and the soot formation rate and yield decreased ***,when the MF heat value ratio was too larg.(75% of the total calorific value),the ig.ition delay period increased,and misfire occurred at the main injection timing.of 0℃A *** RCCI mode of MF/diesel dual fuel has better stability,and better control effect can be obtained at different main inj ection timing.

关键词： 2-methylfuran RCCI visualization two-color method KL factor