Chemical simulation teaching system based on virtual reality and gesture interaction

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.

Implication of Water-Rock Interaction for Enhancing Shale Gas Production

Horizontal well drilling and multi-stage hydraulic fracturing technologies are at the root of commercial shale gas development and exploitation.During these processes,typically,a large amount of working fluid enters the formation,resulting in widespread water-rock interaction.Deeply understanding such effects is required to optimize the production system.In this study,the mechanisms of water-rock interaction and the associated responses of shale fabric are systematically reviewed for working fluids such as neutral fluids,acid fluids,alkali fluids and oxidative fluids.It is shown that shale is generally rich in water-sensitive components such as clay minerals,acidsensitive components(like carbonate minerals),alkali-sensitive components(like quartz),oxidative-sensitive components(like organic matter and pyrite),which easily lead to change of rock fabric and mechanical properties owing to water-rock interaction.According to the results,oxidizing acid fluids and oxidizing fracturing fluids should be used to enhance shale gas recovery.This study also indicates that an aspect playing an important role in increasing cumulative gas production is the optimization of the maximum shut-in time based on the change point of the wellhead pressure drop rate.Another important influential factor to be considered is the control of the wellhead pressure considering the stress sensitivity and creep characteristics of the fracture network.

Groundwater monitoring of an open-pit limestone quarry:Water-rock interaction and mixing estimation within the rock layers by geochemical and statistical analyses

Water-rock interaction and groundwater mixing are important phenomena in understanding hydrogeological systems and the stability of rock slopes especially those consisting largely of moderately watersoluble minerals like calcite. In this study, the hydrogeological and geochemical evolutions of groundwater in a limestone quarry composed of three strata: limestone layer(covering), interbedded layer under the covering layer, and slaty greenstone layer(basement) were investigated. Water-rock interaction in the open-pit limestone quarry was evaluated using PHREEQC, while hierarchical cluster analysis(HCA)and principal component analysis(PCA) were used to classify and identify water sources responsible for possible groundwater mixing within rock layers. In addition, Geochemist's Workbench was applied to estimate the mixing fractions to clarify sensitive zones that may affect rock slope stability. The results showed that the changes in Ca2+and HCO3àconcentrations of several groundwater samples along the interbedded layer could be attributed to mixing groundwater from the limestone layer and that from slaty greenstone layer. Based on the HCA and PCA results, groundwaters were classified into several types depending on their origin:(1) groundwater from the limestone layer(LO),(2) mixed groundwater flowing along the interbedded layer(e.g., groundwater samples L-7, L-11, S-3 and S-4), and(3) groundwater originating from the slaty greenstone layer(SO). The mixing fractions of 41% LO: 59% SO, 64% LO: 36% SO, 43%LO: 57% SOand 25% LO: 75% SOon the normal days corresponded to groundwaters L-7, L-11, S-3 and S-4,respectively, while the mixing fractions of groundwaters L-7 and L-11(61% LO: 39% SOand 93% LO: 7% SO,respectively) on rainy days became the majority of groundwater originating from the limestone layer.These indicate that groundwater along the interbedded layer significantly affected the stability of rock slopes by enlarging multi-breaking zones in the layer through calcite dissolution and inducing high water pressure, tension cracks and potential sliding plane along this layer particularly during intense rainfall episodes.

Interactions between gas flow and reversible chemical reaction in porous media

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.

Chemical interaction motivated structure design of layered metal carbonate hydroxide/MXene composites for fast and durable lithium ion storage

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.

Gel-Based Chemical Cross-Linking Analysis of 20S Proteasome Subunit-Subunit Interactions in 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.

Importance of Metal－Oxide Support Wettingandinteractions on Understanding of Physical and Chemical Behaviours of Supported Metal Catalysts

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.

Water/Rock Interactions and Changes in Chemical Composition During Zeolite Mineralization

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.

Simulation of chemical kinetics in sodium-concrete interactions

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.

Uncovering Chemical Interactions between Danshen and Danggui Using Liquid Chromatography–Mass Spectrometry and Network Pharmacology-Based Research on Stroke

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.

Hydrochemical characteristics and water quality evaluation of shallow groundwater in Suxian mining area,Huaibei coalfield,China

The aim of this study is to evaluate the hydrogeochemical characteristics and water environmental quality of shallow groundwater in the Suxian mining area of Huaibei coalfield,China.The natural formation process of shallow groundwater in Suxian is explored using Piper trilinear charts and Gibbs diagrams,and by examining the ratios between the major ions.United States Salinity Laboratory(USSL)charts,Wilcox diagrams,and the water quality index(WQI)are further employed to quantify the differences in water quality.The results reveal that the main hydrochemical facies of groundwater are HC03-Ca,and that silicate dissolution is the main factor controlling the ion content in shallow groundwater.The USSL charts and Wilcox diagrams show that most of the water samples would be acceptable for use in irrigation systems.The WQI results for each water sample are compared and analyzed,and the quality of groundwater samples around collapse ponds is found to be relatively poor.

Interfacial Interaction of Aggregate-Cement Paste in Concrete

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.

Harnessing chemical functions of ionic liquids for perovskite solar cells

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.

Interaction Theory of Asphalt and Rubber

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.

Stress Relaxation of Chemically Treated Wood during Processes of Temperature Elevation and Decline

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.

Water Quality Assessment in the Bamoun Plateau, Western-Cameroon: Hydrogeochemical Modelling and Multivariate Statistical Analysis Approach

This study focuses on the geochemical and bacteriological investigation of surface and ground water in the Bamoun plateau (Western-Cameroon). During the period from September 2013 to August 2014, 71 samples were collected from two springs, one borehole, four wells and the Nchi stream for analysis of major elements. In order to obtain the characteristics of the various species of bacteria, 7 samples were selected. The analytical method adopted for this study is the conventional hydrochemical technic and multivariate statistical analysis, coupled with the hydrogeochemical modelling. The results revealed that, water from the zone under study are acidic to basic, very weakly to weakly mineralized. Four types of water were identified: 1) CaMg-HCO3;2) CaMg-Cl-SO4;3) NaCl-SO4 and 4) NaK-HCO3. The major elements were all listed in the World Health Organization guidelines for drinking water quality, except for nitrates which was found at a concentration > 50 mg /l NO-3 in the borehole F401. As for the hydrobiological aspect, the entire sample contained all the bacteriological species except for spring S301 and well P401. According to the hydrogeochemical modelling, the Gibbs model and multivariate statistical tests, the quality of surface and ground water of the Foumban locality is influenced by two important factors: 1) the natural factors characterized by the water-rock interaction, evapotranspiration/crystallization, 2) the anthropogenic factors such as: uncontrolled discharges of liquid and solid effluents of all kinds and without any prior treatment within the ground and the strong urbanization accompanied by lack of sanitation and insufficient care.

Chemical Composition of Some Saline Lakes in the Tuva Region(Russia)

1 Introduction Salt lakes are very interesting natural objects which can be found in different places in the world.Russia is not an exception.Climate conditions are various in Russia,but the climate is not very hot.In Russia there are a lot of places where salt lakes are spread.One of them is the Tuva region where lakes with different compositions are

Lagrangian simulation of multi-step and rate-limited chemical reactions in multi-dimensional porous media

Management of groundwater resources and remediation of groundwater pollution require reliable quantification of contaminant dynamics in natural aquifers, which can involve complex chemical dynamics and challenge traditional modeling approaches. The kinetics of chemical reactions in groundwater are well known to be controlled by medium heterogeneity and reactant mixing, motivating the development of particle-based Lagrangian approaches. Previous Lagrangian solvers have been limited to fundamental bimolecular reactions in typically one-dimensional porous media. In contrast to other existing studies, this study developed a fully Lagrangian framework, which was used to simulate diffusion-controlled, multi-step reactions in one-, two-, and three-dimensional porous media. The interaction radius of a reactant molecule, which controls the probability of reaction, was derived by the agent-based approach for both irreversible and reversible reactions. A flexible particle tracking scheme was then developed to build trajectories for particles undergoing mixing-limited, multi-step reactions. The simulated particle dynamics were checked against the kinetics for diffusion-controlled reactions and thermodynamic wellmixed reactions in one-and two-dimensional domains. Applicability of the novel simulator was further tested by(1) simulating precipitation of calcium carbonate minerals in a two-dimensional medium, and(2) quantifying multi-step chemical reactions observed in the laboratory. The flexibility of the Lagrangian simulator allows further refinement to capture complex transport affecting chemical mixing and hence reactions.

Studies on the Erythromycin-Modified Glassy Carbon Electrod and Interaction with DNA

The chemically modified electrode (CME) which was constructed by covalent attaching erythromycin (ERM) to the glassy carbon (GC) surface was investigated in Tris-HCl buffer (pH=6.0) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In the potential range of -0.5～0.4V, CME yields a pair of stable redox wave. It is the carbonyl group of the ERM molecule immobilized on the GC surface that undergoes two electron redox process involving two protons. The interaction of CME with DNA was also studied by DPV. The CME shows the same interaction with DNA as that in the solution. And the result was proved by fluorescence.