Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based ...Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based on virtual reality and gesture interaction.Methods The parameters of the models were obtained through actual investigation,whereby Blender and 3DS MAX were used to model and import these parameters into a physics engine.By establishing an interface for the physics engine,gesture interaction hardware,and virtual reality(VR)helmet,a highly realistic chemical experiment environment was created.Using code script logic,particle systems,as well as other systems,chemical phenomena were simulated.Furthermore,we created an online teaching platform using streaming media and databases to address the problems of distance teaching.Results The proposed system was evaluated against two mainstream products in the market.In the experiments,the proposed system outperformed the other products in terms of fidelity and practicality.Conclusions The proposed system which offers realistic simulations and practicability,can help improve the high school chemistry experimental education.展开更多
The Koyna region of Maharashtra located in the western part of the~65 Myr old Deccan traps province,overlying the Neoarchean cratonic granitoid basement of peninsular India,has been experiencing recurring seismicity s...The Koyna region of Maharashtra located in the western part of the~65 Myr old Deccan traps province,overlying the Neoarchean cratonic granitoid basement of peninsular India,has been experiencing recurring seismicity since 1962 after the impoundment of the Shivajisagar Reservoir behind the Koyna Dam.展开更多
Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite ...Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite volume method on the basis of the gas-solid reaction aA(g)+bB(s)cC(g)+dD(s).The numerical analysis shows that the equilibrium constant is an important factor influencing the process of gas-solid reaction. The stoichiometric coefficients, molar masses of reactant gas, product gas and inert gas are the main factors influencing the density of gas mixture. The equilibrium constant influences the gas flow in porous media obviously when the stoichiometric coefficients satisfy a/c≠1.展开更多
Rational architecture design has turned out to be an effective strategy in improving the electrochemical performance of electrode materials for batteries.However,an elaborate structure that could simultaneously endow ...Rational architecture design has turned out to be an effective strategy in improving the electrochemical performance of electrode materials for batteries.However,an elaborate structure that could simultaneously endow active materials with promoted reaction reversibility,accelerated kinetic and restricted volume change still remains a huge challenge.Herein,a novel chemical interaction motivated structure design strategy has been proposed,and a chemically bonded Co(CO_(3))_(0.5)OH·0.11 H_(2)O@MXene(CoCH@MXene)layered-composite was fabricated for the first time.In such a composite,the chemical interaction between Co^(2+)and MXene drives the growth of smaller-sized CoCH crystals and the subsequent formation of interwoven CoCH wires sandwiched in-between MXene nanosheets.This unique layered structure not only encourages charge transfer for faster reaction dynamics,but buffers the volume change of CoCH during lithiation-delithiation process,owing to the confined crystal growth between conductive MXene layers with the help of chemical bonding.Besides,the sandwiched interwoven CoCH wires also prevent the stacking of MXene layers,further conducive to the electrochemical performance of the composite.As a result,the as-prepared CoCH@MXene anode demonstrates a high reversible capacity(903.1 mAh g^(-1)at 100 mA g^(-1))and excellent cycling stability(maintains 733.6 mAh g^(-1)at1000 mA g^(-1)after 500 cycles)for lithium ion batteries.This work highlights a novel concept of layerby-layer chemical interaction motivated architecture design for futuristic high performance electrode materials in energy storage systems.展开更多
The ubiquitin-proteasome system plays a pivotal role in breast tumorigenesis by controlling transcription factors, thus promoting cell cycle growth, and degradation of tumor suppressor proteins. However, breast cancer...The ubiquitin-proteasome system plays a pivotal role in breast tumorigenesis by controlling transcription factors, thus promoting cell cycle growth, and degradation of tumor suppressor proteins. However, breast cancer patients have failed to benefit from proteasome inhibitor treatment partially due to proteasome heterogeneity, which is poorly understood in malignant breast neoplasm. Chemical crosslinking is an increasingly important tool for mapping protein three-dimensional structures and proteinprotein interactions. In the present study, two cross-linkers, bis(sulfosuccinimidyl) suberate(BS3) and its water-insoluble analog disuccinimidyl suberate(DSS), were used to map the subunit-subunit interactions in 20 S proteasome core particle(CP) from MDA-MB-231 cells. Different types of gel electrophoresis technologies were used. In combination with chemical cross-linking and mass spectrometry, we applied these gel electrophoresis technologies to the study of the noncovalent interactions among 20 S proteasome subunits. Firstly, the CP subunit isoforms were profiled. Subsequently, using native/SDSPAGE, it was observed that 0.5 mmol/L BS^3 was a relatively optimal cross-linking concentration for CP subunit-subunit interaction study. 2-DE analysis of the cross-linked CP revealed that α1 might preinteract with α2, and α3 might pre-interact with α4. Moreover, there were different subtypes of α1α2 and α3α4 due to proteasome heterogeneity. There was no significant difference in cross-linking pattern for CP subunits between BS3 and DSS. Taken together, the gel-based characterization in combination with chemical cross-linking could serve as a tool for the study of subunit interactions within a multi-subunit protein complex. The heterogeneity of 20 S proteasome subunit observed in breast cancer cells may provide some key information for proteasome inhibition strategy.展开更多
It has been generally recognised that the metal catalysts supported on oxide ceramic and non-oxide ceramic supports exhibit completely different characteristics as compared with the homogeneous ones. The na-ture of bo...It has been generally recognised that the metal catalysts supported on oxide ceramic and non-oxide ceramic supports exhibit completely different characteristics as compared with the homogeneous ones. The na-ture of bonding and interactions occurring at the metal / ceramic interfaces are believed to be of importancefor the characteristics of such catalysts. The recently developed microscopic theory of adhesion and wettingin metal/ ceramic systems is briefly presented here with the emphasis on the ionocovalent oxide ceramics.and its consequence on the understanding of the physical and chemical behaviours of supported metal cata-lysts is exploited.展开更多
The objective of this study is to presume cesium corrosion process and its dominant factors in SUS316 steel, a fuel cladding material for fast breeder reactor application, based on both experimental results of cesium ...The objective of this study is to presume cesium corrosion process and its dominant factors in SUS316 steel, a fuel cladding material for fast breeder reactor application, based on both experimental results of cesium corrosion out-pile test and thermodynamic consideration. The cesium corrosion test was performed in simulated environment of high burn-up fuel pin. And main corrosion products in the specimen after the corrosion test were specified by TEM (transition electron microscopy) and SEM (scanning electron microscopy) in order to formulate a hypothesis of the cesium corrosion process. At the end of this study, it was found that the dominant factors of the corrosion process are the amount of cesium on the surface of the specimen, chromium content in the alloy, the supply rate of oxygen and temperature.展开更多
Systematic analysis and comparative study of the chemical compositions of rocks and ores from the main types of zeolite deposits in the surroundings of the Songliao Basin have shown that the process of formation of ze...Systematic analysis and comparative study of the chemical compositions of rocks and ores from the main types of zeolite deposits in the surroundings of the Songliao Basin have shown that the process of formation of zeolite from volcanic and pyroclastic rocks is generally characterized by the relative purification of SiO\-2, i.e., SiO\-2/Al\-2O\-3 ratios tend to increase, alkali earth elements (CaO+MgO) and H\-2O are relatively enriched, and the alkali metals (K\-2O+Na\-2O) are depleted in their total amount. The alkali metals K and Na follow different rules of migration and enrichment during the formation of mordenite and clinoptilolite. In the process of formation of mordenite more Na\++ will be imported and K\++ will be lost remarkably. On the contrary, in the process of formation clinoptilolite more K\++ will be incorporated and Na\++ will become obviously depleted.展开更多
Sodium-concrete interaction is a key safety-related issue in safety analysis of liquid metal cooled fast breeder reactors (LMFBRs). The chemical kinetics model is a key component of the sodium-concrete interaction mod...Sodium-concrete interaction is a key safety-related issue in safety analysis of liquid metal cooled fast breeder reactors (LMFBRs). The chemical kinetics model is a key component of the sodium-concrete interaction model. Conservation equations integrated in sodium-concrete interaction model cannot be solved without a set of re-lationships that couple the equations together, and this may be done by the chemical kinetics model. Simultaneously, simulation of chemical kinetics is difficult due to complexity of the mechanism of chemical reactions between sodium and concrete. This paper describes the chemical kinetics simulation under some hypotheses. The chemical kinetics model was integrated with the conservation equations to form a computer code. Penetration depth, penetration rate, hydrogen flux, reaction heat, etc. can be provided by this code. Theoretical models and computational procedure were recounted in detail. Good agreements of an overall transient behavior were obtained in a series of sodium-concrete interaction experiment analysis. Comparison between analytical and experimental results showed that the chemical kinetics model presented in this paper was creditable and reasonable for simulating the sodium-concrete interactions.展开更多
High-pressure(HP)or ultrahigh-pressure(UHP)rutile-quartz veins that form at mantle depths due to fluid-rock interaction can be used to trace the properties and behavior of natural fluids in subduction zones.To explore...High-pressure(HP)or ultrahigh-pressure(UHP)rutile-quartz veins that form at mantle depths due to fluid-rock interaction can be used to trace the properties and behavior of natural fluids in subduction zones.To explore the fluid flow and the associated element mobility during deep subduction and exhumation of the continental crust,we investigated the major and trace elements of Ti-rich minerals.Additionally,U–Pb dating,trace element contents,and Lu–Hf isotopic composition of zircon grains in the UHP eclogite and associated rutile-quartz veins were examined in the North Qaidam UHP metamorphic belt,Yuka terrane.The zircon grains in the rutile-quartz veins have unzoned or weak oscillatory zonings,and show low Th/U ratios,steep chondrite-normalized patterns of heavy rare earth elements(HREEs),and insignificant negative Eu anomalies,indicating their growth in metamorphic fluids.These zircon grains formed in 4313 Ma,which is consistent with the 4322 Ma age of the host eclogite.As for the zircons in the rutile-quartz veins,they showed steep HREE patterns on one hand,and were different from the zircons present in the host eclogite on the other.This demonstrates that their formation might have been related to the breakdown of the early stage of garnet,which corresponds to the abundance of fluids during the early exhumation stage.The core-rim profile analyses of rutile recorded a two-stage rutile growth across a large rutile grain;the rutile core has higher Nb,Ta,W,and Zr contents and lower Nb/Ta ratios than the rim,indicating that the rutile domains grew in different metamorphic fluids from the core towards the rim.The significant enrichment of high field strength elements(HFSEs)in the rutile core suggests that the peak fluids have high solubility and transportation capacity of these HFSEs.Furthermore,variations in the Nb vs.Cr trends in rutile indicate a connection of rutile to mafic protolith.The zircon grains from both the rutile-quartz veins and the host eclogite have similar Hf isotopic compositions,indicating that the vein-forming fluids are internally derived from the host eclogite.These fluids accumulated in the subduction channel and were triggered by local dehydration of the deeply subducted eclogite during the early exhumation conditions.展开更多
As demonstrated by a great amount of geologic and experimental evidences, RE of rock systems may be mobilized during fluid-rock interaction when solutions are rich in F -, Cl -, CO 3 2-, HCO 3 -, CO 2, HPO 4...As demonstrated by a great amount of geologic and experimental evidences, RE of rock systems may be mobilized during fluid-rock interaction when solutions are rich in F -, Cl -, CO 3 2-, HCO 3 -, CO 2, HPO 4 2-, HS -, S 2-, SO 4 2-, though little has been known about the mobilizing mechanism of these anions or ligands. The fractionation of RE resulted from hydrothermal alterations, i. e., fluid-rock interactions, are distinctive. One set of field data implies the preferential mobility of the LRE, while another set of field observations demonstrates the dominant mobilization of the HRE, and some theoretical prediction is not consistent with the field evidence. The Eu anomalies caused by fluid-rock interaction are complex and compelling explanation is not available due to inadequate experimental approaches. To know the exact behavior of RE during fluid-rock interaction and to solve the contradiction between some theoretical predictions and field observations, the following works remain to be done: (1) experimental investigations of RE mobility and fractionation as a function of fluid chemistry, e.g., the activity of F -, Cl -, CO 3 2-, HCO 3 -, CO 2, HPO 4 2-, HS -, S 2-, SO 4 2-, etc.; (2) experimental determination of RE mobility and fractionation as a function of T, P, pH, E h and water/rock ratios; (3) investigation of the mechanism and the controlling factors of RE partitioning between hydrothermal minerals and fluids. It was demonstrated that RE mobility is a potentially useful method for exploration.展开更多
Objective: The objective of this study was to decipher chemical interactions between Danshen and Danggui using liquid chromatography–mass spectrometry(LC-MS) and explore the mechanisms of Danshen–Danggui against str...Objective: The objective of this study was to decipher chemical interactions between Danshen and Danggui using liquid chromatography–mass spectrometry(LC-MS) and explore the mechanisms of Danshen–Danggui against stroke using network pharmacology and molecular docking. Materials and Methods: First, the chemical compounds of Danshen–Danggui were profiled using ultra-high-performance liquid chromatography(HPLC)-quadrupole time-of-flight MS. Accurately characterized compounds in various proportions of Danshen–Danggui were quantified using HPLC combined with triple quadrupole electrospray tandem MS. Network pharmacology was used to uncover the essential mechanisms of action of Danshen–Danggui against stroke. Discovery Studio Software was used for the molecular docking verification of key active chemicals and stroke-related targets. Results: A total of 53 compounds were characterized, and 22 accurately identified constituents(10 phenolic acids, 8 phthalides, and 4 tanshinones) were quantified in 15 proportions of Danshen–Danggui. The quantification results showed that Danggui significantly increased the dissolution of most phenolic acids(compounds from Danshen), whereas Danshen promoted the dissolution of most phthalides(compounds from Danggui). Overall, the combination of Danshen and Danggui at a 1:1 ratio resulted in the maximum total dissolution rate. Further network pharmacology and molecular docking results indicated that Danshen–Danggui exerted anti-stroke effects mainly by regulating inflammation-related(tumor necrosis factor, hypoxia-inducible factor, and toll-like receptor) signaling pathways, which ranked among the top three pathways based on Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis. Conclusion: The chemical compounds in Danshen–Danggui could interact with each other to increase the dissolution of the most active compounds, which could provide a solid basis for uncovering the compatibility mechanisms of Danshen–Danggui and Danshen–Danggui-based formulae.展开更多
Rare earths in ores, altered and unaltered sericite phyllite, altered and unaltered dacite porphyry were determined in order to examine behaviors of rare earths in hydrothermal alteration associating with ore-forming ...Rare earths in ores, altered and unaltered sericite phyllite, altered and unaltered dacite porphyry were determined in order to examine behaviors of rare earths in hydrothermal alteration associating with ore-forming processes of Yinshan deposit. It is not sufficient to show the mobility only by the absolute abundance of trace elements changes before and after alteration. This can simply result from dilution or concentration if other elements are added to or removed from the rock. As shown by that in Yinshan deposit, less than 20% of the increment of RE was caused by the 'condensed' of leaching some of major elements (e.g. Si, Na) from the rock. The principal factor which should be responsible for the higher contents of RE in altered rock is the addition of RE into the rock by hydrothermal fluids. Eu is selectively leached from the altered sericite phyllite by a mild acidity and reducing fluid which is characterized by much lower LRE/HRE ratio and a large positive Eu anomaly. A major effect on the RE patterns is the tendency to develop relatively flatter chondrite-normalized patterns. The RE characteristics may be used to distinguish between small and large ore bodies at a later stage of exploration.展开更多
The chemical and physical interactions in the interfacial transition zone (ITZ) between three different types of coarse aggregates (limestone, granite and basalt) and cement paste were investigated. The results sh...The chemical and physical interactions in the interfacial transition zone (ITZ) between three different types of coarse aggregates (limestone, granite and basalt) and cement paste were investigated. The results show that all the aggregates are chemically active. Significant amounts of Ca2+, K+, and Na+ are absorbed by all the aggregates from the cement solution, granite and basalt also absorb significant amounts of OH- and release significant amounts of Si4+ into cement solution. The XRD, EDXA and pore structure results of the ITZ also show that more clinkers participate in the cement hydration in the ITZ of granite and basalt, and more hydrates are generated, hence resulting in a denser ITZ structure with a lower content of maeropores. Although the limestone has the least activity, the connection between it and cement paste is tight, due to its rough surface and higher water absorption. Whereas the granite with smooth surface and lower water absorption has a loose connection with cement paste, many pores and cracks are visible, which is very detrimental to the concrete durability.展开更多
The remarkable ramping of record power conversion efficiencies in perovskite solar cells(PSCs) has stimulated the growth of this technology towards commercialization. However, there remain challenges and opportunities...The remarkable ramping of record power conversion efficiencies in perovskite solar cells(PSCs) has stimulated the growth of this technology towards commercialization. However, there remain challenges and opportunities for further improving their efficiency and stability. Featuring the variety of functional group in the constituting ions, ionic liquids(ILs) exhibit versatile properties and functions that can be leveraged to the development of improved PSCs. Herein with a systematic review on the recent progress in the application of ILs to PSCs, we show that based on the different roles of ILs in the film and device settings, IL can facilitate the thin-film synthesis of perovskites, improve the properties of chargetransport layers, and ameliorate the interfacial energetics at device interfaces. In particular, the ILsperovskite interactions of two different types(Lewis acid-base interaction and hydrogen bonding) are the essential chemistries underpinning observed efficiency and stability improvements in PSCs, which represent a vast research paradigm in the field of energy chemistry.展开更多
Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses (Central Zone of the Limpopo Complex) suggest that the formation of the...Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses (Central Zone of the Limpopo Complex) suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-(K, Na)Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-(K, Na)CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.展开更多
Through scanning electron microscope (SEM), spectral analysis, and component analysis tests, the interaction theory between asphalt and rubber was discussed. It is concluded that rubber powder become soft and bond t...Through scanning electron microscope (SEM), spectral analysis, and component analysis tests, the interaction theory between asphalt and rubber was discussed. It is concluded that rubber powder become soft and bond together with each other after being mixed with asphalt. The asphalt changes from a smooth homogeneous matter to a continuous mixing system which is composed of rubber powder and asphalt. The interaction is mainly physical diffusion, but there are some chemical reactions in the process, especially at long reaction time.展开更多
In order to clarify the effect of drying on structural changes of DMSO swell treated and DEA-SO2-DMSO decrystallization treated Chinese fir (Cunninghamia lanceolate) wood, the stress relaxation of treated oven-dry s...In order to clarify the effect of drying on structural changes of DMSO swell treated and DEA-SO2-DMSO decrystallization treated Chinese fir (Cunninghamia lanceolate) wood, the stress relaxation of treated oven-dry specimens during the processes of temperature elevation and reduction and that of treated wet specimens at constant temperature were determined. A stress decrease process and a stress increase process were observed in all stress ratio curves of wood during the processes of decreasing temperature. Untreated wood, during the process of temperature reduction under higher initial temperature conditions and during the process of temperature elevation, has a larger stress decrease than treated woods. In a wet state this trend is reversed. It indicated that the drying set made treated woods have a smaller increase in fluidity of wood constituents with increasing temperature. Some bonding between decrystallization reagents and wood molecules may occur.展开更多
基金National Innovation and Entrepreneurship Program for College Students(202218213001)Science and Technology Innovation Strategy of Guangdong Province(Science and Technology Innovation Cultivation of University Students 2020329182130C000002).
文摘Background Most existing chemical experiment teaching systems lack solid immersive experiences,making it difficult to engage students.To address these challenges,we propose a chemical simulation teaching system based on virtual reality and gesture interaction.Methods The parameters of the models were obtained through actual investigation,whereby Blender and 3DS MAX were used to model and import these parameters into a physics engine.By establishing an interface for the physics engine,gesture interaction hardware,and virtual reality(VR)helmet,a highly realistic chemical experiment environment was created.Using code script logic,particle systems,as well as other systems,chemical phenomena were simulated.Furthermore,we created an online teaching platform using streaming media and databases to address the problems of distance teaching.Results The proposed system was evaluated against two mainstream products in the market.In the experiments,the proposed system outperformed the other products in terms of fidelity and practicality.Conclusions The proposed system which offers realistic simulations and practicability,can help improve the high school chemistry experimental education.
基金conducted under the project sponsored by the Ministry of Earth Sciences,Govt.of India[Project Code-Mo ES/P.O.(Seismo)/1(374)/2019]
文摘The Koyna region of Maharashtra located in the western part of the~65 Myr old Deccan traps province,overlying the Neoarchean cratonic granitoid basement of peninsular India,has been experiencing recurring seismicity since 1962 after the impoundment of the Shivajisagar Reservoir behind the Koyna Dam.
基金Projects(51304035,50974030)supported by the National Natural Science Foundation of ChinaProject(20110491512)supported by the Postdoctoral Science Foundation of China+2 种基金Project(20130042120034)supported by the Specialized Research Fund for the Doctoral Program of Higher Education(New Teachers),ChinaProject(120401008)supported by the Fundamental Research Funds for Central Universities,ChinaProject(L20150173)supported by the Scientific Research Fund of Liaoning Provincial Education Department,China
文摘Taking into consideration the gas compressibility and chemical reaction reversibility, a model was developed to study the interactions between gas flow and chemical reaction in porous media and resolved by the finite volume method on the basis of the gas-solid reaction aA(g)+bB(s)cC(g)+dD(s).The numerical analysis shows that the equilibrium constant is an important factor influencing the process of gas-solid reaction. The stoichiometric coefficients, molar masses of reactant gas, product gas and inert gas are the main factors influencing the density of gas mixture. The equilibrium constant influences the gas flow in porous media obviously when the stoichiometric coefficients satisfy a/c≠1.
基金financially supported by the National Natural Science Foundation of China(No.51933007,No.51673123 and No.22005346)the National Key R&D Program of China(No.2017YFE0111500)+1 种基金the State Key Laboratory of Polymer Materials Engineering(Grant No.:sklpme2020-1-02)Financial support provided by the Fundamental Research Funds for the Central Universities(No.YJ202118)。
文摘Rational architecture design has turned out to be an effective strategy in improving the electrochemical performance of electrode materials for batteries.However,an elaborate structure that could simultaneously endow active materials with promoted reaction reversibility,accelerated kinetic and restricted volume change still remains a huge challenge.Herein,a novel chemical interaction motivated structure design strategy has been proposed,and a chemically bonded Co(CO_(3))_(0.5)OH·0.11 H_(2)O@MXene(CoCH@MXene)layered-composite was fabricated for the first time.In such a composite,the chemical interaction between Co^(2+)and MXene drives the growth of smaller-sized CoCH crystals and the subsequent formation of interwoven CoCH wires sandwiched in-between MXene nanosheets.This unique layered structure not only encourages charge transfer for faster reaction dynamics,but buffers the volume change of CoCH during lithiation-delithiation process,owing to the confined crystal growth between conductive MXene layers with the help of chemical bonding.Besides,the sandwiched interwoven CoCH wires also prevent the stacking of MXene layers,further conducive to the electrochemical performance of the composite.As a result,the as-prepared CoCH@MXene anode demonstrates a high reversible capacity(903.1 mAh g^(-1)at 100 mA g^(-1))and excellent cycling stability(maintains 733.6 mAh g^(-1)at1000 mA g^(-1)after 500 cycles)for lithium ion batteries.This work highlights a novel concept of layerby-layer chemical interaction motivated architecture design for futuristic high performance electrode materials in energy storage systems.
基金supported by the National Natural Science Foundation of China(No.81202095)the Research Fund for the Doctoral Program of Higher Education of China(No.20120142120053)the Hubei Provincial Natural Science Foundation of China(No.2013CFB134)
文摘The ubiquitin-proteasome system plays a pivotal role in breast tumorigenesis by controlling transcription factors, thus promoting cell cycle growth, and degradation of tumor suppressor proteins. However, breast cancer patients have failed to benefit from proteasome inhibitor treatment partially due to proteasome heterogeneity, which is poorly understood in malignant breast neoplasm. Chemical crosslinking is an increasingly important tool for mapping protein three-dimensional structures and proteinprotein interactions. In the present study, two cross-linkers, bis(sulfosuccinimidyl) suberate(BS3) and its water-insoluble analog disuccinimidyl suberate(DSS), were used to map the subunit-subunit interactions in 20 S proteasome core particle(CP) from MDA-MB-231 cells. Different types of gel electrophoresis technologies were used. In combination with chemical cross-linking and mass spectrometry, we applied these gel electrophoresis technologies to the study of the noncovalent interactions among 20 S proteasome subunits. Firstly, the CP subunit isoforms were profiled. Subsequently, using native/SDSPAGE, it was observed that 0.5 mmol/L BS^3 was a relatively optimal cross-linking concentration for CP subunit-subunit interaction study. 2-DE analysis of the cross-linked CP revealed that α1 might preinteract with α2, and α3 might pre-interact with α4. Moreover, there were different subtypes of α1α2 and α3α4 due to proteasome heterogeneity. There was no significant difference in cross-linking pattern for CP subunits between BS3 and DSS. Taken together, the gel-based characterization in combination with chemical cross-linking could serve as a tool for the study of subunit interactions within a multi-subunit protein complex. The heterogeneity of 20 S proteasome subunit observed in breast cancer cells may provide some key information for proteasome inhibition strategy.
文摘It has been generally recognised that the metal catalysts supported on oxide ceramic and non-oxide ceramic supports exhibit completely different characteristics as compared with the homogeneous ones. The na-ture of bonding and interactions occurring at the metal / ceramic interfaces are believed to be of importancefor the characteristics of such catalysts. The recently developed microscopic theory of adhesion and wettingin metal/ ceramic systems is briefly presented here with the emphasis on the ionocovalent oxide ceramics.and its consequence on the understanding of the physical and chemical behaviours of supported metal cata-lysts is exploited.
文摘The objective of this study is to presume cesium corrosion process and its dominant factors in SUS316 steel, a fuel cladding material for fast breeder reactor application, based on both experimental results of cesium corrosion out-pile test and thermodynamic consideration. The cesium corrosion test was performed in simulated environment of high burn-up fuel pin. And main corrosion products in the specimen after the corrosion test were specified by TEM (transition electron microscopy) and SEM (scanning electron microscopy) in order to formulate a hypothesis of the cesium corrosion process. At the end of this study, it was found that the dominant factors of the corrosion process are the amount of cesium on the surface of the specimen, chromium content in the alloy, the supply rate of oxygen and temperature.
基金ThisstudywassupportedjointlybytheNationalNaturalScienceFoundationofChina (No .40 0 72 0 30 )andtheProgramspon soredbytheMinistry
文摘Systematic analysis and comparative study of the chemical compositions of rocks and ores from the main types of zeolite deposits in the surroundings of the Songliao Basin have shown that the process of formation of zeolite from volcanic and pyroclastic rocks is generally characterized by the relative purification of SiO\-2, i.e., SiO\-2/Al\-2O\-3 ratios tend to increase, alkali earth elements (CaO+MgO) and H\-2O are relatively enriched, and the alkali metals (K\-2O+Na\-2O) are depleted in their total amount. The alkali metals K and Na follow different rules of migration and enrichment during the formation of mordenite and clinoptilolite. In the process of formation of mordenite more Na\++ will be imported and K\++ will be lost remarkably. On the contrary, in the process of formation clinoptilolite more K\++ will be incorporated and Na\++ will become obviously depleted.
基金Supported by National Natural Science Foundation of China (Grant No. 19785002)
文摘Sodium-concrete interaction is a key safety-related issue in safety analysis of liquid metal cooled fast breeder reactors (LMFBRs). The chemical kinetics model is a key component of the sodium-concrete interaction model. Conservation equations integrated in sodium-concrete interaction model cannot be solved without a set of re-lationships that couple the equations together, and this may be done by the chemical kinetics model. Simultaneously, simulation of chemical kinetics is difficult due to complexity of the mechanism of chemical reactions between sodium and concrete. This paper describes the chemical kinetics simulation under some hypotheses. The chemical kinetics model was integrated with the conservation equations to form a computer code. Penetration depth, penetration rate, hydrogen flux, reaction heat, etc. can be provided by this code. Theoretical models and computational procedure were recounted in detail. Good agreements of an overall transient behavior were obtained in a series of sodium-concrete interaction experiment analysis. Comparison between analytical and experimental results showed that the chemical kinetics model presented in this paper was creditable and reasonable for simulating the sodium-concrete interactions.
基金funded by the Fundamental Research Funds for National Universities, China University of Geosciences (Wuhan) and China Geological Survey (Grant Nos. 12120113032800, 21201011000150004, DD20190069)
文摘High-pressure(HP)or ultrahigh-pressure(UHP)rutile-quartz veins that form at mantle depths due to fluid-rock interaction can be used to trace the properties and behavior of natural fluids in subduction zones.To explore the fluid flow and the associated element mobility during deep subduction and exhumation of the continental crust,we investigated the major and trace elements of Ti-rich minerals.Additionally,U–Pb dating,trace element contents,and Lu–Hf isotopic composition of zircon grains in the UHP eclogite and associated rutile-quartz veins were examined in the North Qaidam UHP metamorphic belt,Yuka terrane.The zircon grains in the rutile-quartz veins have unzoned or weak oscillatory zonings,and show low Th/U ratios,steep chondrite-normalized patterns of heavy rare earth elements(HREEs),and insignificant negative Eu anomalies,indicating their growth in metamorphic fluids.These zircon grains formed in 4313 Ma,which is consistent with the 4322 Ma age of the host eclogite.As for the zircons in the rutile-quartz veins,they showed steep HREE patterns on one hand,and were different from the zircons present in the host eclogite on the other.This demonstrates that their formation might have been related to the breakdown of the early stage of garnet,which corresponds to the abundance of fluids during the early exhumation stage.The core-rim profile analyses of rutile recorded a two-stage rutile growth across a large rutile grain;the rutile core has higher Nb,Ta,W,and Zr contents and lower Nb/Ta ratios than the rim,indicating that the rutile domains grew in different metamorphic fluids from the core towards the rim.The significant enrichment of high field strength elements(HFSEs)in the rutile core suggests that the peak fluids have high solubility and transportation capacity of these HFSEs.Furthermore,variations in the Nb vs.Cr trends in rutile indicate a connection of rutile to mafic protolith.The zircon grains from both the rutile-quartz veins and the host eclogite have similar Hf isotopic compositions,indicating that the vein-forming fluids are internally derived from the host eclogite.These fluids accumulated in the subduction channel and were triggered by local dehydration of the deeply subducted eclogite during the early exhumation conditions.
文摘As demonstrated by a great amount of geologic and experimental evidences, RE of rock systems may be mobilized during fluid-rock interaction when solutions are rich in F -, Cl -, CO 3 2-, HCO 3 -, CO 2, HPO 4 2-, HS -, S 2-, SO 4 2-, though little has been known about the mobilizing mechanism of these anions or ligands. The fractionation of RE resulted from hydrothermal alterations, i. e., fluid-rock interactions, are distinctive. One set of field data implies the preferential mobility of the LRE, while another set of field observations demonstrates the dominant mobilization of the HRE, and some theoretical prediction is not consistent with the field evidence. The Eu anomalies caused by fluid-rock interaction are complex and compelling explanation is not available due to inadequate experimental approaches. To know the exact behavior of RE during fluid-rock interaction and to solve the contradiction between some theoretical predictions and field observations, the following works remain to be done: (1) experimental investigations of RE mobility and fractionation as a function of fluid chemistry, e.g., the activity of F -, Cl -, CO 3 2-, HCO 3 -, CO 2, HPO 4 2-, HS -, S 2-, SO 4 2-, etc.; (2) experimental determination of RE mobility and fractionation as a function of T, P, pH, E h and water/rock ratios; (3) investigation of the mechanism and the controlling factors of RE partitioning between hydrothermal minerals and fluids. It was demonstrated that RE mobility is a potentially useful method for exploration.
基金funded by the State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Guangxi Normal University) (CMEMR2022-B11)National Natural Science Foundation of China (822044593)Natural Science Foundation of Jiangsu Higher Education Institutions of China (22KJB360018)。
文摘Objective: The objective of this study was to decipher chemical interactions between Danshen and Danggui using liquid chromatography–mass spectrometry(LC-MS) and explore the mechanisms of Danshen–Danggui against stroke using network pharmacology and molecular docking. Materials and Methods: First, the chemical compounds of Danshen–Danggui were profiled using ultra-high-performance liquid chromatography(HPLC)-quadrupole time-of-flight MS. Accurately characterized compounds in various proportions of Danshen–Danggui were quantified using HPLC combined with triple quadrupole electrospray tandem MS. Network pharmacology was used to uncover the essential mechanisms of action of Danshen–Danggui against stroke. Discovery Studio Software was used for the molecular docking verification of key active chemicals and stroke-related targets. Results: A total of 53 compounds were characterized, and 22 accurately identified constituents(10 phenolic acids, 8 phthalides, and 4 tanshinones) were quantified in 15 proportions of Danshen–Danggui. The quantification results showed that Danggui significantly increased the dissolution of most phenolic acids(compounds from Danshen), whereas Danshen promoted the dissolution of most phthalides(compounds from Danggui). Overall, the combination of Danshen and Danggui at a 1:1 ratio resulted in the maximum total dissolution rate. Further network pharmacology and molecular docking results indicated that Danshen–Danggui exerted anti-stroke effects mainly by regulating inflammation-related(tumor necrosis factor, hypoxia-inducible factor, and toll-like receptor) signaling pathways, which ranked among the top three pathways based on Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis. Conclusion: The chemical compounds in Danshen–Danggui could interact with each other to increase the dissolution of the most active compounds, which could provide a solid basis for uncovering the compatibility mechanisms of Danshen–Danggui and Danshen–Danggui-based formulae.
文摘Rare earths in ores, altered and unaltered sericite phyllite, altered and unaltered dacite porphyry were determined in order to examine behaviors of rare earths in hydrothermal alteration associating with ore-forming processes of Yinshan deposit. It is not sufficient to show the mobility only by the absolute abundance of trace elements changes before and after alteration. This can simply result from dilution or concentration if other elements are added to or removed from the rock. As shown by that in Yinshan deposit, less than 20% of the increment of RE was caused by the 'condensed' of leaching some of major elements (e.g. Si, Na) from the rock. The principal factor which should be responsible for the higher contents of RE in altered rock is the addition of RE into the rock by hydrothermal fluids. Eu is selectively leached from the altered sericite phyllite by a mild acidity and reducing fluid which is characterized by much lower LRE/HRE ratio and a large positive Eu anomaly. A major effect on the RE patterns is the tendency to develop relatively flatter chondrite-normalized patterns. The RE characteristics may be used to distinguish between small and large ore bodies at a later stage of exploration.
基金Funded by the National Nature Science Foundation of China(No.51108282)Natural Science Foundation of Hebei Province of China(No.E2011210025)+1 种基金Excellent Youth Scholars of University Science and Technology Research of Hebei Province(No.Y2011111)Hebei Key Discipline Construction Project
文摘The chemical and physical interactions in the interfacial transition zone (ITZ) between three different types of coarse aggregates (limestone, granite and basalt) and cement paste were investigated. The results show that all the aggregates are chemically active. Significant amounts of Ca2+, K+, and Na+ are absorbed by all the aggregates from the cement solution, granite and basalt also absorb significant amounts of OH- and release significant amounts of Si4+ into cement solution. The XRD, EDXA and pore structure results of the ITZ also show that more clinkers participate in the cement hydration in the ITZ of granite and basalt, and more hydrates are generated, hence resulting in a denser ITZ structure with a lower content of maeropores. Although the limestone has the least activity, the connection between it and cement paste is tight, due to its rough surface and higher water absorption. Whereas the granite with smooth surface and lower water absorption has a loose connection with cement paste, many pores and cracks are visible, which is very detrimental to the concrete durability.
基金financial support from the Taishan Scholars Project of Shandong Province (201909121)the start-up grants, Initiation Grant - Faculty Niche Research Areas (IG-FNRA) 2020/21 and Interdisciplinary Matching Scheme 2020/21 of the Hong Kong Baptist University (HKBU) and the Early Career Scheme (22300221) from the Hong Kong Research Grant Councilthe support of the Hong Kong Ph D Fellowship Scheme。
文摘The remarkable ramping of record power conversion efficiencies in perovskite solar cells(PSCs) has stimulated the growth of this technology towards commercialization. However, there remain challenges and opportunities for further improving their efficiency and stability. Featuring the variety of functional group in the constituting ions, ionic liquids(ILs) exhibit versatile properties and functions that can be leveraged to the development of improved PSCs. Herein with a systematic review on the recent progress in the application of ILs to PSCs, we show that based on the different roles of ILs in the film and device settings, IL can facilitate the thin-film synthesis of perovskites, improve the properties of chargetransport layers, and ameliorate the interfacial energetics at device interfaces. In particular, the ILsperovskite interactions of two different types(Lewis acid-base interaction and hydrogen bonding) are the essential chemistries underpinning observed efficiency and stability improvements in PSCs, which represent a vast research paradigm in the field of energy chemistry.
基金supported by Russian Foundation for Basic Research(project 10-05-00040 to OGS)Russian President Grants for Young Scientists(MD-222.2012.5 to OGS)+1 种基金grant from the National Science Foundation of South Africa(GUN:20531 92 to DDvR)University of Johannesburg as a part of the Russian South African scientific collaboration
文摘Reaction textures and fluid inclusions in the -2.0 Ga pyroxene-bearing dehydration zones within the Sand River biotite-hornblende orthogneisses (Central Zone of the Limpopo Complex) suggest that the formation of these zones is a result of close interplay between dehydration process along ductile shear zones triggered by H2O-CO2-salt fluids at 750--800 ℃ and 5.5--6.2 kbar, partial melting, and later exsolution of residual brine and H2O-CO2 fluids during melt crystallization at 650--700 ℃. These processes caused local variations of water and alkali activity in the fluids, resulting in various mineral assemblages within the dehydration zone. The petrological observations are substantiated by experiments on the interaction of the Sand River gneiss with the H2O-CO2-(K, Na)Cl fluids at 750 and 800 ℃ and 5.5 kbar. It follows that the interaction of biotite-amphibole gneiss with H2O-CO2-(K, Na)CI fluids is accompanied by partial melting at 750--800 ℃. Orthopyroxene-bearing assemblages are characteristic for temperature 800 ℃ and are stable in equilibrium with fluids with low salt concentrations, while salt-rich fluids produce clinopyroxene-bearing assemblages. These observations are in good agreement with the petrological data on the dehydration zones within the Sand River olthogneisses.
基金Funded by Jiangsu Transportation Research Program(No. 05Y07)
文摘Through scanning electron microscope (SEM), spectral analysis, and component analysis tests, the interaction theory between asphalt and rubber was discussed. It is concluded that rubber powder become soft and bond together with each other after being mixed with asphalt. The asphalt changes from a smooth homogeneous matter to a continuous mixing system which is composed of rubber powder and asphalt. The interaction is mainly physical diffusion, but there are some chemical reactions in the process, especially at long reaction time.
基金Supported by the National Natural Science Foundation of China (Grant No. 30070606)Graduate Cultivation Foundation of Beijing Forestry University(Grant No. 304)
文摘In order to clarify the effect of drying on structural changes of DMSO swell treated and DEA-SO2-DMSO decrystallization treated Chinese fir (Cunninghamia lanceolate) wood, the stress relaxation of treated oven-dry specimens during the processes of temperature elevation and reduction and that of treated wet specimens at constant temperature were determined. A stress decrease process and a stress increase process were observed in all stress ratio curves of wood during the processes of decreasing temperature. Untreated wood, during the process of temperature reduction under higher initial temperature conditions and during the process of temperature elevation, has a larger stress decrease than treated woods. In a wet state this trend is reversed. It indicated that the drying set made treated woods have a smaller increase in fluidity of wood constituents with increasing temperature. Some bonding between decrystallization reagents and wood molecules may occur.