The high-temperature molten salt pump is the core equipment in a molten salt reactor that drives the flow of the molten salt coolant.Rotor stability is key to the continuous and reliable operation of the molten salt p...The high-temperature molten salt pump is the core equipment in a molten salt reactor that drives the flow of the molten salt coolant.Rotor stability is key to the continuous and reliable operation of the molten salt pump,and the liquid seal at the wear ring can affect the dynamic characteristics of the rotor system.When the molten salt pump is operated in the hightemperature molten salt medium,thermal deformation of the submerged parts inevitably occurs,changing clearance between the stator and rotor,affecting the leakage and dynamic characteristics of the seal.In this study,the seal leakage,seal dynamic characteristics,and rotor system dynamic characteristics are simulated and analyzed using finite element simulation software based on two cases of considering the effect of seal thermal deformation effect or not.The results show a significant difference in the leakage characteristics and dynamic characteristics of the seal obtained by considering the effect of seal thermal deformation and neglecting the effect of thermal deformation.The leakage flow rate decreases,and the first-order critical speed of the seal-bearing-rotor system decrease after considering the seal’s thermal deformation.展开更多
The transcription factor early growth response protein 3(EGR3)is involved in schizophrenia.We developed a putative rat model of schizophrenia by transfecting lentiviral particles carrying the Egr3gene into bilateral h...The transcription factor early growth response protein 3(EGR3)is involved in schizophrenia.We developed a putative rat model of schizophrenia by transfecting lentiviral particles carrying the Egr3gene into bilateral hippocampal dentate gyrus.We assessed spatial working memory using the Morris water maze test,and neuronal metabolite levels in bilateral hippocampus and thalamus were determined by 3.0 T proton magnetic resonance spectroscopy.Choline content was significantly greater in the hippocampus after transfection,while N-acetylaspartate and the ratio of N-acetylaspartate to creatine/phosphocreatine in the thalamus were lower than in controls.This study is the first to report evaluation of brain metabolites using 3.0 T proton magnetic resonance spectroscopy in rats transfected with Egr3,and reveals metabolic abnormalities in the hippocampus and thalamus in this putative model of schizophrenia.展开更多
To improve the reliability and reduce energy consumption,a conceptual design of a freeze valve is proposed for the thorium-based molten salt reactor(TMSR)concept.Fins were utilized in this new design to enhance heat t...To improve the reliability and reduce energy consumption,a conceptual design of a freeze valve is proposed for the thorium-based molten salt reactor(TMSR)concept.Fins were utilized in this new design to enhance heat transfer and realize passive shut-off function,which could not be realized by the previous design.An experimental apparatus using the fluoride salt FLiNaK was constructed to conduct a series of preliminary solidification and melting experiments.In addition,the enthalpy-porosity method of ANSYS■Fluent solver was applied to simulate the solidification process of the salt at a specified operating temperature.Temperature distributions of the fluoride salt,solidification/melting time,and frozen plug effect were analyzed under natural convection heat transfer in an open space.The calculated salt temperatures exhibited good agreement with the experimental values.The results indicated that the range of effective operating temperature is 530-600℃ for the finned freeze valve.In this study,the ideal set operating temperature of the finned freeze valve was chosen as 560℃ to achieve competent performance.Moreover,560℃ is additionally the highest set operating temperature for maintaining excellent cooling performance and sustaining deep-frozen condition of the salt plug.At this set operating temperature,the simulation data indicated that the molten salt in the flat part of the finned freeze valve will completely solidify at 10.5 min.The percentage of solid salt in the flat and lower transitional parts of the valve reaches 29.60% in 30.0 min.Furthermore,the surface temperature of the proposed freeze valve is 11.10% lower compared with that of the TMSR freeze valve at a cooling gas supply of 173 m^3/h.Therefore,the new freeze valve was proven to be capable of reducing the energy consumption and realizing the passive shut-off function.展开更多
Molten salt pump is applied to pump high-temperature molten salt as the primary coolant of a molten salt reactor.The pump,generally a vertical rotor system,suffers from radial force generated by the liquid seal compon...Molten salt pump is applied to pump high-temperature molten salt as the primary coolant of a molten salt reactor.The pump,generally a vertical rotor system,suffers from radial force generated by the liquid seal component,and the rotordynamic characteristics of the pump are affected considerably.In this paper,the rotordynamic coefficients of the tooth-on-stator liquid seal in molten salt pump are studied.The flow in the seal region is simulated using computational fluid dynamics technique.Parameters of the inlet loss and the pre-swirl at the inlet region of the seal are calculated.The coefficients of resistance and the wall parameters are obtained from the simulation results by data fitting method.The rotordynamic coefficients are analyzed based on the bulk-flow model of liquid seal.The rotordynamic characteristics,with and without the liquid seal,of the objective molten salt pump are inspected.The first critical speed of the rotor is found to increase.Harmonic analysis shows that the pump,being sensitive to unbalance force though,can operate safely under its design specifications.展开更多
We consider a two-way relay network where the Amplify-and-Forward (AF) protocol is adopted by all relays in this paper.The network consists of two multi-antenna source nodes and multiple distributed single-antenna rel...We consider a two-way relay network where the Amplify-and-Forward (AF) protocol is adopted by all relays in this paper.The network consists of two multi-antenna source nodes and multiple distributed single-antenna relays.Two opportunistic relaying schemes are proposed to efficiently utilize the antennas of the source nodes and the relay nodes.In the first scheme,the best relay is selected out by a max-min-max criterion before transmitting.After that,at each source,only the antenna with the largest channel gain between itself and the best relay is activated to transmit and receive signals with full power.In the second scheme,assisted by the best relay which is selected by the typical max-min criterion,both source nodes use all their antennas to exchange data,and match filter beamforming techniques are employed at both source nodes.Further analyses show that all schemes can achieve the full diversity order,and the conclusions are not only mathematically demonstrated but numerically illustrated.System performance comparisons are carried out by numerical methods in terms of rate sum and outage probability,respectively.The beamforming assisted scheme can be found to be superior to the antenna selection scheme when accurate Channel State Information (CSI) is available at the transmitters.Otherwise,the latter is very suitable.展开更多
Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive dysfunction. Currently there is no effective treatment. Given the depth of current stem cell research,...Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive dysfunction. Currently there is no effective treatment. Given the depth of current stem cell research, researchers have attempted to compensate for neuronal loss in the brains of patients with Alzheimer's disease using stem cell technology. This article will review the pathogenesis of AD, the latest advances in stem cell therapy, and the challenges and prospects of its development.展开更多
Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma(WM/LPL) is a low-grade B-cell nonHodgkin's lymphoma with an indolent clinical course.Higher-grade non-Hodgkin lymphoma(NHL) and therapyrelated myelody...Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma(WM/LPL) is a low-grade B-cell nonHodgkin's lymphoma with an indolent clinical course.Higher-grade non-Hodgkin lymphoma(NHL) and therapyrelated myelodysplasia/acute leukemia(t-MDS/AML) have been reported in patients with WM/LPL in previous studies.However,only two cases with WM/LPL were reported to develop to Hodgkin lymphoma(HL).Here,we report the first case of WM/LPL who developed classical HL simultaneously 3 years after initial nucleoside analog-based chemotherapy.展开更多
Objective:To construct a recombinant lentiviral vector that co-express ZsGreen and BDNF and establish an Adipose derived stem cell (ADSC) line with stable BDNF expression down- regulation.Methods: BDNF were designed a...Objective:To construct a recombinant lentiviral vector that co-express ZsGreen and BDNF and establish an Adipose derived stem cell (ADSC) line with stable BDNF expression down- regulation.Methods: BDNF were designed and inserted into the lentiviral vector p HBLV-CMVIE-Zs Green-Puro. After identification by DNA sequencing, the lentiviral vectors carrying BDNF were packaged in 293 cells. The transfection efficiency was observed under fluorescence microscope;the lentiviral particles were collected to infect mouse ADSCs, and BDNF level were assessed using real-time PCR and Western blotting.Results: DNA sequencing demonstrated successful construction of the BDNF lentivirus vectors. Real- time PCR and Western blotting showed a high level BDNF mRNA and protein.Conclusion: We have successfully established an ADSC model with stable BDNF expression which establish the basis for the potential application of ADSCs-BDNF in the treatment of AD.展开更多
Perovskite nanocrystals(PNCs)/polymer nanocomposites can combine the advantages of each other,but extremely few works can achieve the fabrication of PNCs/polymer nanocomposites by bulk polymerization.We originally ado...Perovskite nanocrystals(PNCs)/polymer nanocomposites can combine the advantages of each other,but extremely few works can achieve the fabrication of PNCs/polymer nanocomposites by bulk polymerization.We originally adopt a two-type ligand strategy to fabricate bulk PNCs/polystyrene(PS)nanocomposites,including a new type of synthetic polymerizable ligand.The CsPbCl_(3)PNCs/PS nanocomposites show extremely high transparency even the doping content up to 5 wt%.The high transparency can be ascribed to the Rayleigh scattering as the PNCs distribute uniformly without obvious aggregation.Based on this behavior,we first exploit the potential of PNCs to serve as scatters inside light guided plate(LGP),whose surface illuminance and uniformity can be improved,and this new kind of LGP is compatible with the advanced liquid crystal display technology.Thanks to the facile composition adjustment of CsPbCl_(x)Br_(3-x)(1≤x≤3)PNCs,the Rayleigh scattering behavior can also be adjusted so as to the performance of LGP.The best-performing 5.0-inch LGP based on CsPbCl_(2.5)Br_(0.5)PNCs/PS nanocomposites shows 20.5 times higher illuminance and 1.8 times higher uniformity in display than the control.The LGP based on PNCs/PS nanocomposite exhibits an enormous potential in commercialization no matter based on itself or combined with the LGP-related technology.展开更多
Background:Cardiac rupture (CR) is a major lethal complication of acute myocardial infarction (AMI).However,no valid risk score model was found to predict CR after AMI in previous researches.This study aimed to establ...Background:Cardiac rupture (CR) is a major lethal complication of acute myocardial infarction (AMI).However,no valid risk score model was found to predict CR after AMI in previous researches.This study aimed to establish a simple model to assess risk of CR after AMI,which could be easily used in a clinical environment.Methods:This was a retrospective case-control study that included 53 consecutive patients with CR after AMI during a period from January 1,2010 to December 31,2017.The controls included 524 patients who were selected randomly from 7932 AMI patients without CR at a 1:10 ratio.Risk factors for CR were identified using univariate analysis and multivariate logistic regression.Risk score model was developed based on multiple regression coefficients.Performance of risk model was evaluated using receiveroperating characteristic (ROC) curves and internal validity was explored using bootstrap analysis.Results:Among all 7985 AMI patients,53 (0.67%) had CR (free wall rupture,n=39;ventricular septal rupture,n=14).Hospital mortalities were 92.5% and 4.01% in patients with and without CR (P<0.001).Independent variables associated with CR included:older age,female gender,higher heart rate at admission,body mass index (BMI)<25 kg/m^2,lower left ventricular ejection fraction (LVEF) and no primary percutaneous coronary intervention (pPCI) treatment.In ROC analysis,our CR risk assess model demonstrated a very good discriminate power (area under the curve [AUC]= 0.895,95% confidence interval:0.845–0.944,optimism-corrected AUC= 0.821,P<0.001).Conclusion:This study developed a novel risk score model to help predict CR after AMI,which had high accuracy and was very simple to use.展开更多
In this study, a vorticity vector-potential method for two-dimensional viscous incompressible rotating driven flows is developed in the time-dependent curvilinear coordinates. The method is applicable in both inertial...In this study, a vorticity vector-potential method for two-dimensional viscous incompressible rotating driven flows is developed in the time-dependent curvilinear coordinates. The method is applicable in both inertial and non-inertial frames of reference with the advantage of a fixed and regular calculation domain. The numerical method is applied to triangle and curved triangle configurations in constant and varying rotational angular velocity cases respectively. The evolutions of flow field are studied. The geostrophic effect, unsteady effect and curvature effect on the evolutions are discussed.展开更多
基金the Strategic Pilot Technology Chinese Academy of Sciences(No.XDA02010500).
文摘The high-temperature molten salt pump is the core equipment in a molten salt reactor that drives the flow of the molten salt coolant.Rotor stability is key to the continuous and reliable operation of the molten salt pump,and the liquid seal at the wear ring can affect the dynamic characteristics of the rotor system.When the molten salt pump is operated in the hightemperature molten salt medium,thermal deformation of the submerged parts inevitably occurs,changing clearance between the stator and rotor,affecting the leakage and dynamic characteristics of the seal.In this study,the seal leakage,seal dynamic characteristics,and rotor system dynamic characteristics are simulated and analyzed using finite element simulation software based on two cases of considering the effect of seal thermal deformation effect or not.The results show a significant difference in the leakage characteristics and dynamic characteristics of the seal obtained by considering the effect of seal thermal deformation and neglecting the effect of thermal deformation.The leakage flow rate decreases,and the first-order critical speed of the seal-bearing-rotor system decrease after considering the seal’s thermal deformation.
文摘The transcription factor early growth response protein 3(EGR3)is involved in schizophrenia.We developed a putative rat model of schizophrenia by transfecting lentiviral particles carrying the Egr3gene into bilateral hippocampal dentate gyrus.We assessed spatial working memory using the Morris water maze test,and neuronal metabolite levels in bilateral hippocampus and thalamus were determined by 3.0 T proton magnetic resonance spectroscopy.Choline content was significantly greater in the hippocampus after transfection,while N-acetylaspartate and the ratio of N-acetylaspartate to creatine/phosphocreatine in the thalamus were lower than in controls.This study is the first to report evaluation of brain metabolites using 3.0 T proton magnetic resonance spectroscopy in rats transfected with Egr3,and reveals metabolic abnormalities in the hippocampus and thalamus in this putative model of schizophrenia.
基金supported by the National Natural Science Foundation of China(No.91326201)the Strategic Pilot Technology Chinese Academy of Sciences(No.XDA0201002)
文摘To improve the reliability and reduce energy consumption,a conceptual design of a freeze valve is proposed for the thorium-based molten salt reactor(TMSR)concept.Fins were utilized in this new design to enhance heat transfer and realize passive shut-off function,which could not be realized by the previous design.An experimental apparatus using the fluoride salt FLiNaK was constructed to conduct a series of preliminary solidification and melting experiments.In addition,the enthalpy-porosity method of ANSYS■Fluent solver was applied to simulate the solidification process of the salt at a specified operating temperature.Temperature distributions of the fluoride salt,solidification/melting time,and frozen plug effect were analyzed under natural convection heat transfer in an open space.The calculated salt temperatures exhibited good agreement with the experimental values.The results indicated that the range of effective operating temperature is 530-600℃ for the finned freeze valve.In this study,the ideal set operating temperature of the finned freeze valve was chosen as 560℃ to achieve competent performance.Moreover,560℃ is additionally the highest set operating temperature for maintaining excellent cooling performance and sustaining deep-frozen condition of the salt plug.At this set operating temperature,the simulation data indicated that the molten salt in the flat part of the finned freeze valve will completely solidify at 10.5 min.The percentage of solid salt in the flat and lower transitional parts of the valve reaches 29.60% in 30.0 min.Furthermore,the surface temperature of the proposed freeze valve is 11.10% lower compared with that of the TMSR freeze valve at a cooling gas supply of 173 m^3/h.Therefore,the new freeze valve was proven to be capable of reducing the energy consumption and realizing the passive shut-off function.
基金funded by the National Natural Science Foundation of China(Nos.51576125 and 51406114)
文摘Molten salt pump is applied to pump high-temperature molten salt as the primary coolant of a molten salt reactor.The pump,generally a vertical rotor system,suffers from radial force generated by the liquid seal component,and the rotordynamic characteristics of the pump are affected considerably.In this paper,the rotordynamic coefficients of the tooth-on-stator liquid seal in molten salt pump are studied.The flow in the seal region is simulated using computational fluid dynamics technique.Parameters of the inlet loss and the pre-swirl at the inlet region of the seal are calculated.The coefficients of resistance and the wall parameters are obtained from the simulation results by data fitting method.The rotordynamic coefficients are analyzed based on the bulk-flow model of liquid seal.The rotordynamic characteristics,with and without the liquid seal,of the objective molten salt pump are inspected.The first critical speed of the rotor is found to increase.Harmonic analysis shows that the pump,being sensitive to unbalance force though,can operate safely under its design specifications.
基金supported by the National Natural Science Foundation of China under Grant No.60902092
文摘We consider a two-way relay network where the Amplify-and-Forward (AF) protocol is adopted by all relays in this paper.The network consists of two multi-antenna source nodes and multiple distributed single-antenna relays.Two opportunistic relaying schemes are proposed to efficiently utilize the antennas of the source nodes and the relay nodes.In the first scheme,the best relay is selected out by a max-min-max criterion before transmitting.After that,at each source,only the antenna with the largest channel gain between itself and the best relay is activated to transmit and receive signals with full power.In the second scheme,assisted by the best relay which is selected by the typical max-min criterion,both source nodes use all their antennas to exchange data,and match filter beamforming techniques are employed at both source nodes.Further analyses show that all schemes can achieve the full diversity order,and the conclusions are not only mathematically demonstrated but numerically illustrated.System performance comparisons are carried out by numerical methods in terms of rate sum and outage probability,respectively.The beamforming assisted scheme can be found to be superior to the antenna selection scheme when accurate Channel State Information (CSI) is available at the transmitters.Otherwise,the latter is very suitable.
基金funded by the National Key Research and Devel-opment Program of China[grant number 2017YFC1501405]the National Natural Science Foundation of China[grant numbers 41975180,41705119,and 41575131]the National Center of Meteorology,Abu Dhabi,AE(UAE Research Program for Rain Enhancement Science)。
基金National Natural Science Foundation of China (81660224,31760310)
文摘Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive memory loss and cognitive dysfunction. Currently there is no effective treatment. Given the depth of current stem cell research, researchers have attempted to compensate for neuronal loss in the brains of patients with Alzheimer's disease using stem cell technology. This article will review the pathogenesis of AD, the latest advances in stem cell therapy, and the challenges and prospects of its development.
文摘Waldenstrom's macroglobulinemia/lymphoplasmacytic lymphoma(WM/LPL) is a low-grade B-cell nonHodgkin's lymphoma with an indolent clinical course.Higher-grade non-Hodgkin lymphoma(NHL) and therapyrelated myelodysplasia/acute leukemia(t-MDS/AML) have been reported in patients with WM/LPL in previous studies.However,only two cases with WM/LPL were reported to develop to Hodgkin lymphoma(HL).Here,we report the first case of WM/LPL who developed classical HL simultaneously 3 years after initial nucleoside analog-based chemotherapy.
基金supported by the National Key R&D Program of Chinagrant number 2018YFC1507900the Demonstration Project of Artificial Precipitation Enhancement and Hail Suppression Operation Technology at the Eastern Side of the Taihang Mountains grant number hbrywcsy-2017-2sponsored by the National Natural Science Foundation of China grant numbers 41530427 and 41875172。
基金The National Natural Science Foundation of China.Project No:(81660224,81100246)Hainan Provincial Key Research and Development Project.Project No:(ZDYF2017120,ZDYF2016110)+2 种基金National College’s Students’Innovation and Entrepreneurship Training Program Project.Project No:(201711810010,HYCX2016010,HYCX2018032)Hainan Provincial Health and Family Planning Industry Research Project.Project No:(18A200115)Haikou People’s Hospital Project.Project No:(2018-SNP-01-003).
文摘Objective:To construct a recombinant lentiviral vector that co-express ZsGreen and BDNF and establish an Adipose derived stem cell (ADSC) line with stable BDNF expression down- regulation.Methods: BDNF were designed and inserted into the lentiviral vector p HBLV-CMVIE-Zs Green-Puro. After identification by DNA sequencing, the lentiviral vectors carrying BDNF were packaged in 293 cells. The transfection efficiency was observed under fluorescence microscope;the lentiviral particles were collected to infect mouse ADSCs, and BDNF level were assessed using real-time PCR and Western blotting.Results: DNA sequencing demonstrated successful construction of the BDNF lentivirus vectors. Real- time PCR and Western blotting showed a high level BDNF mRNA and protein.Conclusion: We have successfully established an ADSC model with stable BDNF expression which establish the basis for the potential application of ADSCs-BDNF in the treatment of AD.
基金This work was financially supported by the National Science Foundation of China(NSFC)under Grant No.52233005.
文摘Perovskite nanocrystals(PNCs)/polymer nanocomposites can combine the advantages of each other,but extremely few works can achieve the fabrication of PNCs/polymer nanocomposites by bulk polymerization.We originally adopt a two-type ligand strategy to fabricate bulk PNCs/polystyrene(PS)nanocomposites,including a new type of synthetic polymerizable ligand.The CsPbCl_(3)PNCs/PS nanocomposites show extremely high transparency even the doping content up to 5 wt%.The high transparency can be ascribed to the Rayleigh scattering as the PNCs distribute uniformly without obvious aggregation.Based on this behavior,we first exploit the potential of PNCs to serve as scatters inside light guided plate(LGP),whose surface illuminance and uniformity can be improved,and this new kind of LGP is compatible with the advanced liquid crystal display technology.Thanks to the facile composition adjustment of CsPbCl_(x)Br_(3-x)(1≤x≤3)PNCs,the Rayleigh scattering behavior can also be adjusted so as to the performance of LGP.The best-performing 5.0-inch LGP based on CsPbCl_(2.5)Br_(0.5)PNCs/PS nanocomposites shows 20.5 times higher illuminance and 1.8 times higher uniformity in display than the control.The LGP based on PNCs/PS nanocomposite exhibits an enormous potential in commercialization no matter based on itself or combined with the LGP-related technology.
文摘Background:Cardiac rupture (CR) is a major lethal complication of acute myocardial infarction (AMI).However,no valid risk score model was found to predict CR after AMI in previous researches.This study aimed to establish a simple model to assess risk of CR after AMI,which could be easily used in a clinical environment.Methods:This was a retrospective case-control study that included 53 consecutive patients with CR after AMI during a period from January 1,2010 to December 31,2017.The controls included 524 patients who were selected randomly from 7932 AMI patients without CR at a 1:10 ratio.Risk factors for CR were identified using univariate analysis and multivariate logistic regression.Risk score model was developed based on multiple regression coefficients.Performance of risk model was evaluated using receiveroperating characteristic (ROC) curves and internal validity was explored using bootstrap analysis.Results:Among all 7985 AMI patients,53 (0.67%) had CR (free wall rupture,n=39;ventricular septal rupture,n=14).Hospital mortalities were 92.5% and 4.01% in patients with and without CR (P<0.001).Independent variables associated with CR included:older age,female gender,higher heart rate at admission,body mass index (BMI)<25 kg/m^2,lower left ventricular ejection fraction (LVEF) and no primary percutaneous coronary intervention (pPCI) treatment.In ROC analysis,our CR risk assess model demonstrated a very good discriminate power (area under the curve [AUC]= 0.895,95% confidence interval:0.845–0.944,optimism-corrected AUC= 0.821,P<0.001).Conclusion:This study developed a novel risk score model to help predict CR after AMI,which had high accuracy and was very simple to use.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11172069,11472082)
文摘In this study, a vorticity vector-potential method for two-dimensional viscous incompressible rotating driven flows is developed in the time-dependent curvilinear coordinates. The method is applicable in both inertial and non-inertial frames of reference with the advantage of a fixed and regular calculation domain. The numerical method is applied to triangle and curved triangle configurations in constant and varying rotational angular velocity cases respectively. The evolutions of flow field are studied. The geostrophic effect, unsteady effect and curvature effect on the evolutions are discussed.
