肿瘤原位荧光标记技术设计和探索虚拟仿真实验

原位荧光成像技术为细胞和活体水平生化信息获取提供了强有力的手段,基于固态发光荧光探针的长时间原位标记技术能应用于精准成像与手术导航肿瘤切除。但该科研实验存在周期长、成本高、消耗大等困难,无法引入本科教学。采用U3D三维虚拟现实技术平台将该最新研究成果转化为“肿瘤原位荧光标记技术设计和探索虚拟仿真实验”,通过37步交互操作和基于重要科学问题的探究式教学,培养学生动手能力、科学思维和创新意识,实现科学素养和科研价值观的引导。

Photoreduction of CO_(2) in the presence of CH_(4) over g-C_(3)N_(4) modified with TiO_(2) nanoparticles at room temperature

CO_(2)reduction under simulated sunlight over photocatalysts has become an attractive researcher area recently.In this work,carbon nitride compounds modified by TiO_(2)nanoparticles(TNPs)have been used for the photoreduction of CO_(2)in the presence of CH_(4)at room temperature.Briefly,a series of noble-metal-free TNP-graphitic-carbon nitride(g-C_(3)N_(4),also abbreviated CN)photocatalysts with different TNPs loadings and calcination temperatures have been synthesized by a wet-chemical method.The characterization results of XRD,FTIR,SEM,TEM,BET,XPS,CO_(2)Adsorption,UV-vis,and PL demonstrate that the BET surface area and CO_(2)adsorption capacity have been improved after the calcination.Besides,the g-C_(3)N_(4)has been successfully coupled with the TNPs and a heterojunction has formed at their interface.These characters contribute to increase the photocatalytic activity of TNPs-CN toward reducing CO_(2)in the presence of CH_(4),and its'performance is better than bare g-C_(3)N_(4),Titania(P_(25))-CN,MgO-CN,or Cu_(2)O-CN.Orthogonal experiments are then carried out to investigate the sensitivity factors and optimum conditions.The sensitivity results show that the reaction pressure makes little difference on the photocatalysis results,which verifies the photoinduced CO_(2)-CH_(4)reaction has a tiny change in gas volume.In addition,under the optimum conditions,the turnover frequency(TOF)of CO after 4 h reaction can reach 9.98μmol g-cat.^(-1)h^(-1),and traces of ethane and ethylene have been detected during the reactions.In addition,surface acetate and carbonaceous deposit are found on the(20)TNPs-CN/450 surface after continuous 24 h irradiation under the optimum conditions,which resulting in the inactivation of the catalyst.Finally,possible reaction mechanisms have been proposed based on the results.

Experimental study of the mass transfer behavior of carbon dioxide absorption into ternary phase change solution in a packed tower

Phase change absorbents for CO_(2)are of great interest because they are expected to greatly reduce the heat energy consumption during the regeneration process.Compared with other phase change absorbents,monoethanolamine(MEA)-sulfolane-water is inexpensive and has a fast absorption rate.It is one of the most promising solvents for large-scale industrial applications.Therefore,this study investigates the mass transfer performance of this phase change system in the process of CO_(2)absorption in a packed tower.By comparing the phase change absorbent and the ordinary absorbent,it is concluded that the use of MEA/sulfolane phase change absorbent has significantly improved mass transfer efficiency compared to a single MEA absorbent at the same concentration.In the 4 mol·L^(-1)MEA/5 mol·L^(-1)sulfolane system,the CO_(2)loading of the upper liquid phase after phase separation is almost zero,while the volume of the lower liquid phase sent to the desorption operation is about half of the total volume of the absorbent,which greatly reduces the energy consumption.This study also investigates the influence of operating parameters such as lean CO_(2)loading,gas and liquid flow rates,CO_(2)partial pressure,and temperature on the volumetric mass transfer coefficient(K_(G)α_(V)).The research shows that K_(G)α_(V) increases with increasing liquid flow rate and decreases with the increase of lean CO_(2)loading and CO_(2)partial pressure,while the inert gas flow rate and temperature have little effect on K_(G)α_(V).In addition,based on the principle of phase change absorption,a predictive equation for the K_(G)α_(V) of MEA-sulfolane in the packed tower was established.The K_(G)α_(V) obtained from the experiment is consistent with the model prediction,and the absolute average deviation(AAD)is 7.8%.

Feasibility analysis and process simulation of CO_(2) dehydration using triethylene glycol for CO_(2) pipeline transportation

The operation of dehydration is very important in the process of gas transportation. This study aims to evaluate the application feasibility of CO_(2) dehydration using triethylene glycol, which is also called TEG for short. Aspen Plus software was used to simulate the dehydration process system of CO_(2) gas transportation using TEG dehydration. Parameter analysis and process improvement were carried out for the simulation of dehydration process. At first, a sensitivity analysis was conducted to analyze and optimize operating conditions of conventional CO_(2)-TEG dehydration process system. Subsequently, a recycle unit was introduced into the conventional CO_(2)-TEG dehydration process system, it can be found that the improved process system with the recycle unit has a higher CO_(2) recovery rate which was about 9.8% than the conventional one. Moreover, the improved process system showed excellent operation stability through the comparison of simulation results of several processes with various water contents in their feed gases. Although the energy consumption is increased by about 2%, the improved process was economically and technically feasible for the long-term availability of CO_(2) pipeline transportation. The simulated results showed that the improved CO_(2)-TEG process system has promising application prospects in CO_(2) dehydration of CO_(2) gas transportation with high stability.

An improved correlation to determine minimum miscibility pressure of CO2–oil system

An accurate and reliable estimation of minimum miscibility pressure(MMP) of CO2-oil system is a critical task for the design and implementation of CO2 miscible displacement process.In this study,an improved CO2-oil MMP correlation was developed to predict the MMP values for both pure and impure CO2 injection cases based on ten influential factors,i.e.reservoir temperature(TR),molecular weight of C7+oil components(MWC7+),mole fraction of volatile oil components(xvol),mole fraction of C2-C4 oil components(xC2-C4),mole fraction of C5-C6 oil components(xCs-5-C6),and the gas stream mole fractions of CO2(yCO2),H2S(yH2S),C1(yC1),hydrocarbons(yHC)and N2(yN2).The accuracy of the improved correlation was evaluated against experimental data reported in literature concurrently with those estimated by several renowned correlations.It was found that the improved correlation provided higher prediction accuracy and consistency with literature experimental data than other literature correlations.In addition,the predictive capability of the improved correlation was further validated by predicting an experimentally measured CO2-Oil MMP data,and it showed an accurate result with the absolute deviation of 4.15%.Besides,the differential analysis of the improved correlation was analyzed to estimate the impact of parameters uncertainty in the original MMP data on the calculated results.Also,sensitivity analysis was performed to analyze the influence of each parameter on MMP qualitatively and quantitatively.The results revealed that the increase of xC2-C4,xC5-C6 and yH2 S lead to the decrease of MMP,while the increase of TR,MWC7+,xvol,yCO2,YC1,yHC and yN2 tend to increase the MMP.Overall,the relevance of each parameter with MMP follows the order of TR> xC5-C6> MWC7+> xvol> yH2 S> yHC> yCO2>yC1>yN2>xC2-C4.

Development of ovalbumin implants with different spatial configurations for treatment of peripheral nerve injury

Peripheral nerve injury(PNI)seriously affects the health and life of patients,and is an urgent clinical problem that needs to be resolved.Nerve implants prepared from various biomaterials have played a positive role in PNI,but the effect should be further improved and thus new biomaterials is urgently needed.Ovalbumin(OVA)contains a variety of bioactive components,low immunogenicity,tolerance,antimicrobial activity,non-toxicity and biodegradability,and has the ability to promote wound healing,cell growth and antimicrobial properties.However,there are few studies on the application of OVA in neural tissue engineering.In this study,OVA implants with different spatial structures(membrane,fiber,and lyophilized scaffolds)were constructed by casting,electrospinning,and freeze-drying methods,respectively.The results showed that the OVA implants had excellent physicochemical properties and were biocompatible without significant toxicity,and can promote vascularization,show good histocompatibility,without excessive inflammatory response and immunogenicity.The in vitro results showed that OVA implants could promote the proliferation and migration of Schwann cells,while the in vivo results confirmed that OVA implants(the E5/70%and 20 kV 20μL/min groups)could effectively regulate the growth of blood vessels,reduce the inflammatory response and promote the repair of subcutaneous nerve injury.Further on,the high-throughput sequencing results showed that the OVA implants up-regulated differential expression of genes related to biological processes such as tumor necrosis factor-α(TNF-α),phosphatidylinositide 3-kinases/protein kinase B(PI3K-Akt)signaling pathway,axon guidance,cellular adhesion junctions,and nerve regeneration in Schwann cells.The present study is expected to provide new design concepts and theoretical accumulation for the development of a new generation of nerve regeneration implantable biomaterials.

Volumetric and viscometric properties of aqueous 1,2-dimethylethylenediamine solution for carbon capture application

The present work investigates the volumetric and viscometric properties of an aqueous solution of 1,2-dimethylethylenediamine(DEEDA)over an entire concentration range and an absorber operating temperature range of 313.15K-333.15K at atmospheric pressure.The investigated volumetric properties included the density,excess molar volume,partial molar volume,and the investigated viscometric properties included the viscosity,viscosity deviation,free energy for activation of viscous flow,excess free energy for activation of viscous flow,and excess entropy for activation of viscous flow.The results indicated that there are strong intermolecular interactions and suitable molecular packing in the binary DEEDA-water mixture.Hence,the mixture was found to deviate from a real mixture according to the calculated excess properties.The DEEDA solvent's preliminary volumetric and viscometric properties revealed convincing potential as a novel amine for carbon capture.Additionally,the Redlich-Kister-based correlations showed favorable correlative performance for excess molar volume,viscosity deviation,and excess entropy for activation of viscous flow.

Modeling and boundary control of a flexible marine riser coupled with internal fluid dynamics

In this paper, vibration reduction of a flexible marine riser with time-varying internal fluid is studied by using boundary control method and Lyapunov＇s direct method. To achieve more accurate and practical riser＇s dynamic behavior, the model of marine riser with time-varying internal fluid is modeled by a distributed parameter system （DPS） with partial differential equations （PDEs） and ordinary differential equations （ODEs） involving functions of space and time. The dynamic responses of riser are completely different if the time-varying internal fluid is considered. Boundary control is designed at the top boundary of the riser based on original infinite dimensionality PDEs model and Lyapunov＇s direct method to reduce the riser＇s vibrations. The uniform boundedness and closed-loop stability are proved based on the proposed boundary control. Simulation results verify the effectiveness of the proposed boundary control.