The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of gr...The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively.展开更多
Based on the working principle and the damping characteristic of hydraulic shock absorber, a fluid structure interaction method was presented, which was used to analyze the microcosmic and high-frequency processing me...Based on the working principle and the damping characteristic of hydraulic shock absorber, a fluid structure interaction method was presented, which was used to analyze the microcosmic and high-frequency processing mechanism of fluid structure interaction between circulation valve and liquid of hydraulic shock absorber. The fluid mesh distortion was controlled by the CEL language, and the fluid struc^tre interaction mathematical model was established. The finite element model was established by ANSYS CFX software and was analyzed by dynamic mesh technique. The local sensitive computational area was meshed by prismatic grid, which could reduce the negative volume problem during the simulation. The circulation valve and liquid of hydraulic shock absorber were simulated and analyzed under the condition of sinusoidal inlet velocity loads. Flow characteristic and dynamics characteristic were obtained. The pressure distribution and the displacement of circulation value were obtained, and the acceleration curve of circulation valve was simulated and analyzed. The conformity of the final simulation results with the experimental datum indicates that this method is accurate and reliable to analyze the dynamics characteristic between circulation valve and liquid of hydraulic shock absorber, which can provide a theoretical foundation for optimizing hydraulic shock absorber in the future.展开更多
At airports, runway operation is the limiting factor for the overall throughput; specifically the fixed and overly conservative ICAO wake turbulence separation minima. The wake turbulence hazardous flows can dissipate...At airports, runway operation is the limiting factor for the overall throughput; specifically the fixed and overly conservative ICAO wake turbulence separation minima. The wake turbulence hazardous flows can dissipate quicker because of decay due to air turbulence or be transported out of the way on oncoming traffic by cross-wind, yet wake turbulence separation minima do not take into account wind conditions. Indeed, for safety reasons, most airports assume a worst-case scenario and use conservative separations; the interval between aircraft taking off or landing therefore often amounts to several minutes. However, with the aid of accurate wind data and precise measurements of wake vortex by radar sensors, more efficient intervals can be set, particularly when weather conditions are stable. Depending on traffic volume, these adjustments can generate capacity gains, which have major commercial benefits. This paper presents the use of Electronic scanning radar for detecting wake vortices. In this method, the raindrops Doppler spectrogram is used to retrieve the strength of the wake vortex. Numerical simulation are performed to establish an empirical model used during the retrieval method. This paper presents also the results obtained during the trials of the PARIS-CDG data set recorded from October 2014 to November 2015 with an X-band RADAR developed and deployed by THALES.展开更多
A safe,economical treatment of hazardous chromium-bearing vanadate residue(CVR)will significantly benefit the clean production of chromate-bearing salts.This study investigated recovery of sodium vanadate and sodium c...A safe,economical treatment of hazardous chromium-bearing vanadate residue(CVR)will significantly benefit the clean production of chromate-bearing salts.This study investigated recovery of sodium vanadate and sodium chromate from CVR in sodium bicarbonate solution.Results indicate that the stability of calcium vanadate and calcium chromate depends on pH and[HCO3?].CaV2O6?4H2O transforms into CaV2O6?4H2O,CaV2O6?2H2O,CaV2O6,Ca2V2O7?2H2O,and Ca5(VO4)3(OH)when pH increases from 7.51 to 12.32.Increasing pH and reducing CVR dosage improve the vanadate extraction rate,and high V2O5 and Na2Cr2O7?2H2O extraction rates are achieved in dilute NaHCO3 solution.Moreover,addition of NaOH positively contributes to the recovery of vanadate and chromate from CVR.Over 95%V2O5 and Na2Cr2O7?2H2O in CVR can be extracted from 60 g/L NaHCO3 and 30 g/L NaOH solutions at 90°C for 2 h.In order to reduce the hazardous residue containing chromate after recovery of CVR,calcium circulation is presented.Results show that more than 60%lime can be saved with fresh residue addition to remove vanadate from sodium chromate solution due to the active CaCO3.Moreover,no lime is required in removal of vanadate when the roasting residue is added.Therefore,a novel process is developed for utilization of CVR.展开更多
A discontinuity of magnetic circuits according to the end effect is generated in the permanent magnet linear synchronous motor （PMLSM）. Due to the unbalanced back electro-motive force （EMF） and impedance produced,...A discontinuity of magnetic circuits according to the end effect is generated in the permanent magnet linear synchronous motor （PMLSM）. Due to the unbalanced back electro-motive force （EMF） and impedance produced, unbalanced current is generated. The cireulatin8 current, which is caused by a decrease in the thrust, is generated by the unbalanced current. The optimal design of auxiliary-teeth at the end of the mover was carried out to solve the unbalance of phase by using design of experiment （DOE）, and compared with the basic model through finite element analysis （FEA）. As a result, the auxiliary-teeth model compensates for the decrease of thrust caused by the unbalanced phase. Also, this model is proven to reduce the detent force by the vibration and noise of the PMLSM and copper loss caused by the circulating current.展开更多
OBJECTIVE Our previous studies demonstrated that various ingredients from the traditional Chinese medicine(TCM)for promoting blood circulation and removing blood stasis,as exemplified by cryptotanshinone and salvianol...OBJECTIVE Our previous studies demonstrated that various ingredients from the traditional Chinese medicine(TCM)for promoting blood circulation and removing blood stasis,as exemplified by cryptotanshinone and salvianolic acid B,exerted striking effects on modulating angiogenesis and vascular permeability,which suggests that they may be effective in treating vascular leak-driven diseases(e.g.tumor,cerebral cavernous malformation and diabetic retinopathy).However,the lack of reliable and advanced technologies and models sets up difficult hurdles for better understanding the role of TCM for promoting blood circulation and removing blood stasis.To this end,this study is to outline numerous cutting-edge platforms that can be utilized for exploring the function of TCM for promoting blood circulation and removing blood stasis in vascular leak-driven diseases.METHODS Two-photon laser scanning fluorescence microscopy was used to observe the interactions between neutrophils and blood vessels in a real-time manner.Dynamic flow system was employed to mimic the in vivo behaviors of neutrophils.RIP1-Tag5 spontaneous pancreatic cancer model was used to study the function of tumor blood vessels.CCM2ECKO(deletion of CCM2 in endothelial cells)mice were employed to establish the cerebral cavernous malformation(CCM)animal model.Micro-computed tomography(micro-CT)was utilized to assess the CCM lesion.Müller cell-knockout mouse model was used to study the progression of diabetic retinopathy.Vascular permeability in this model was assessed by fluorescein angiography.RESULTS The interactions between neutrophils and endothelial cells involve a series of complicated processes,including rolling,adhesion,intraluminal crawling and transmigration,which were all monitored in vivo by two-photon laser scanning fluorescence microscopy in a real-time manner.Dynamic flow system was capable of recapitulating the biological behaviors of neutrophils in vitro.Tumor vascular function in particular vascular perfusion could be assessed in the RIP1-Tag5 spontaneous pancreatic cancer model.In terms of CCM studies,specific deletion of CCM2 in endothelial cells resulted in the initiation of CCM lesion.The size and number of CCM lesions could be visualized and quantified by micro-CT.Furthermore,the Müller cell-knockout mouse model was able to precisely reflect the clinical symptoms of diabetic retinopathy.Vascular leak could be monitored at different time points using fluorescein angiography.CONCLUSION An array of high technologies and animal models can be used in investigating the occurrence and progression of multiple vascular leak-driven diseases.The pre-clinical and clinical studies of TCM for promoting blood circulation and removing blood stasis provide fundamental support for the application of the above-mentioned platforms,with the purpose of uncovering the scientific basis of TCM for promoting blood circulation and removing blood stasis.展开更多
The summer and winter circulations in the South China Sea (SCS) including the surface elevation and water temperature are simulated using the model described by Cai and Li (1996) with the monthly mean wind stress and ...The summer and winter circulations in the South China Sea (SCS) including the surface elevation and water temperature are simulated using the model described by Cai and Li (1996) with the monthly mean wind stress and air temperature field at the 1000 mb level from the European Centre for Medium-Range Weather Forecasts as inputs. The boundary conditions at Bashi Channel and Taiwan Strait are taken from the simulation results of the Kuroshio using the same numerical model with a grid size of 0.5°×0.5° and the results of Cai and Li (1996) as boundary conditions. The computational domain for the present paper is between 100°E and 123°E and between 4.5°N and 27°N. The horizontal resolution is 0.25°×0.25° and the vertical variations of the velocity components are resolved by 6 layers The computed steady flow, temperature and elevation fields are consistent with the corresponding fields observed. In particular, the temperature and elevation fields of the South China Sea Warm Current (SCSWC) have been successfully simulated. The paths of the branch of the Kuroshio entering the South China Sea (SCSBK) through Bashi Channel in winter and summer are discussed It is found that the SCSBK flows southward to the southern SCS from the coast of the Guangdong Province. A portion of the SCSBK returns to the Bashi Channel and subdivides again in deep waters in winter with a branch flows to the south along the coast of the Philippines instead of flowing back to the Pacific In addition, our results confirm the existence of a eastward current to the northeast of Dongsha in summer with the Kuroshio as its source as suggested by Huang et al. Since the value of the eddy viscosity adopted for the simulation of the Kuroshio is on the high side, resulting in a weaker west boundary current in the western Pacific as the boundary conditions for the present simulations, some deviations from the actual situations are expected although the results are in general consistent with observations.展开更多
Efficient and reliable removal of cellulose,hemicellulose and lignin,that are the major organic pollutants in the wastewater from regenerated fiber,is critically important to prevent toxicity discharge.Low-and high-pH...Efficient and reliable removal of cellulose,hemicellulose and lignin,that are the major organic pollutants in the wastewater from regenerated fiber,is critically important to prevent toxicity discharge.Low-and high-pH stresses sometimes occur in the effluent treatment systems due to the use of a large amount of acid and alkaline in the pulping process.Using flat separation method to select high-yield strains from bio-contact oxidation basin,seeing configuration of the strains and doing some physiological experiments,we found that the strains contain two kinds of main bacteria,Zoogloea sp.and Pseudomona sp.We also discovered the best growing time by spectrophotometer.The best growing time is at 0～32h,the logarithmic phase is about at 12～32h,and the stable growth phase is about 32～60h.Furthermore,we concluded that the disposal ability of high-yield strain is better than the ordinary one by doing parallel experiment.Through orthogonal test we also confirmed that the best growing temperature and pH value are 29℃and 7.3 respectively.The COD removal rate is about 93% when the biomembrane is in good condition.展开更多
This essay examines current-event plays( shishiju 时事剧) and their social functions in late Ming China. Drawing on awide range or primary sources and built on secondary scholarship on information history,the essay of...This essay examines current-event plays( shishiju 时事剧) and their social functions in late Ming China. Drawing on awide range or primary sources and built on secondary scholarship on information history,the essay offered a complete picture of the booming,features,social functions and the decline of the current-event plays. The essay argues that many current-event plays addressed on credibility,timeliness and easy accessibility,which enabled current-event plays to play an important role in information circulation. This essay further exposes the current-event plays not only opened a forum for public discussion but also influenced public opinions greatly from literate elites to the masses in Ming China. Through analyzing current-event plays in the context of Ming society,this essay expands the realm of studying information history.展开更多
Base on dynamic analysis for a Front Wheel Assist (FWA) tractor, a method of calculating and analyzing on the critical angle of steering for a FWA tractor is described in this paper. The mathematical model is also est...Base on dynamic analysis for a Front Wheel Assist (FWA) tractor, a method of calculating and analyzing on the critical angle of steering for a FWA tractor is described in this paper. The mathematical model is also established here. The critical steering angle which is a important parameter affecting the steering performance for a FWA tractor is defined in the article.展开更多
In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbul...In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.展开更多
The popularly used circulant matrix model of deconvolution is mostly heavily ill-posed or singular and it is not suitable to many blind deconvolution problems. The aperiodic matrix model can improve the condition numb...The popularly used circulant matrix model of deconvolution is mostly heavily ill-posed or singular and it is not suitable to many blind deconvolution problems. The aperiodic matrix model can improve the condition number of deconvolution problems and its accommodation is much wider than the circulant one's. This paper discusses a comparison of the two models including their ill-posedness, the rationality of the approximation by the models, and their computational efficiency. The comparison shows that the aperiodic model is promising in the development of new restoration algorithms.展开更多
A comparative study of the influence of elevated temperature on foam geopolymer using circulating fluidized bed combustion fly ash（CFA） was reported. Foam geopoymers were prepared with different amounts of foam agen...A comparative study of the influence of elevated temperature on foam geopolymer using circulating fluidized bed combustion fly ash（CFA） was reported. Foam geopoymers were prepared with different amounts of foam agent and different Si O2/Al2O3 molar ratios of 3.1, 3.4, and 3.8. The mechanical, thermo-physical properties and microstructure of the foam geopolymers before and after exposure to elevated temperature of 800, 1000, and 1200 ℃ were investigated. The specimen with Si O2/Al2O3 molar ratio of 3.8 exhibits the highest compressive strength, better microstructure and dimension stability before and after firing. Carnegeite, nepheline, and zeolite crystalline phases appearing after exposure may contribute to the good post-exposure strength. Low weight foam geopolymer using CFA can increase strength and maintain higher stability as high as 1000 ℃.展开更多
In this paper, a new design method for high performance octave-band stripline circulator is given. The optimum design program is given by a construction with double-Y junction aided by a section of quarter-wavelength ...In this paper, a new design method for high performance octave-band stripline circulator is given. The optimum design program is given by a construction with double-Y junction aided by a section of quarter-wavelength impedance transformer. All the calculation is simpler than that given by Y. S. Wu, et al[1-7]. Typical performances of the 2-4GHz Y-junction stripline circulator are insertion loss 0.35dB (max), isolation 21dB (min), VSWR 1.25 (max). An octave low-loss and high isolation performance is demonstrated without the need of repeated design cycles.展开更多
It is critical to combat tumor metastasis by eradicating disseminated tumor cells in any step during the metastasis process.After entering the blood circulation system,tumor cells are in suspension and experience cons...It is critical to combat tumor metastasis by eradicating disseminated tumor cells in any step during the metastasis process.After entering the blood circulation system,tumor cells are in suspension and experience considerable levels of fluid shear stress.However,the influence of hemodynamic shear stress on the survival of CTCs and the underlying mechanotransduction mechanisms remain unclear.This study shows that fluid shear stress can eliminate the majority of CTCs and the viability of suspended tumor cells depends on the stress magnitude,indicating that tumor cells can sense and respond to fluid shear stress.Mechanistically,the expression of Piezo1 but not Piezo2 is greatly upregulated in suspended tumor cells after shear stress treatment.Inhibiting/activating Piezo1 increases/decreases the viability of suspended tumor cells in shear flow,which depends on Piezo1-mediated calcium entry.These findings suggest that Piezo1 may be the major mechanosensor by which suspended tumor cells sense fluid shear stress.As the downstream effector of Piezo1,actomyosin in tumor cells is significantly activated under increasing shear stress.Its activity influences the survival of CTCs in shear flow and rescues the effects of Piezo1 on tumor cell survival,suggesting that hemodynamic shear stress regulates the survival of CTCs through Piezo1 mediated actomyosin activity.Importantly,fluid shear stress considerably up-regulates YAP/TAZ activity of suspended tumor cells and promotes their nuclear translocation in a magnitude-dependent manner.Inhibiting YAP/TAZ enhances the viability of suspended tumor cells in shear stress,while activating their activity decreases tumor cell survival,suggesting that YAP/TAZ activation promotes the apoptosis of suspended tumor cells,which is different from the findings that YAP/TAZ facilitates the survival of adherent cells to shear flow.Further,blocking the nuclear import of YAP/TAZ inactivates the sensation of suspended tumor cells to fluid shear flow and attenuates the dependence of tumor cell survival on different magnitudes of hemodynamic shear stress.The influence of Piezo1-actomyosin pathway on suspended tumor cells can be rescued by YAP/TAZ activity,suggesting that Piezo1-mediated signaling induces tumor cell apoptosis via nuclear translocation of YAP/TAZ.In addition,fluid shear stress can also activate the expressions of LATS1/2 and MST1/2 in Hippo pathway through Piezo1,which is known to inhibit YAP/TAZ activity.Silencing/activating LATS1/2 or MST1/2 inhibits/enhances the viability of CTCs under shear stress,the effects of which can be further rescued by YAP/TAZ.These findings suggest that the responses of suspended tumor cells to hemodynamic shear stress are partially mediated by Hippo signaling.After nuclear translocation,YAP/TAZ directly bind p73/PUMA,which further promotes the transcription of pro-apoptotic genes and induces the apoptosis of suspended tumor cells.In summary,these findings show that hemodynamic shear stress considerably influences the survival of CTCs in blood circulation.We have identified the calcium channel Piezo1 as a novel mechanosensor for the response of CTCs to fluid shear stress.Hemodynamic shear stress induces the apoptosis of suspended tumor cells through Piezo1-actomyosin-YAP/TAZ-p73/PUMA signaling,which is different from the mechanotranduction mechanisms for tumor cells in adherent.Therefore,this study has unveiled the novel mechanosensor of suspended CTCs in response to fluid shear stress and the subsequent mechanisms and identified Piezo1 and YAP/TAZ as the potential therapeutic targets,through which CTCs may be effectively eradicated in the vasculature to prohibit tumor metastasis.展开更多
文摘The start-up of external circulationadded internal circulation(IC) reactor was finished in 26 d, 32 d fewer than that of IC reactor. To evaluate the influence of the added external circulation on the development of granular sludge, the characteristics of the granular sludge taken from the two tested laboratory-scale reactors during start-up were studied. The results show that the added external circulation can enhance biomass granulation, accelerate granule development and improve sludge characteristics. At the end of start-up, the granular size of sludge in external circulation-added IC reactor greatly increases with a size distribution much better than that of sludge in IC reactor. The granular sludge originated from external circulationadded IC reactor contains more extracellular polymers and has a greater settling velocity than that from IC reactor. Methanogenic activity of the granular sludge from the external circulationadded IC reactor started 26 d ago reaches 358.23mL·g -1 ·d -1 , 1.66 and 1.20 times as great as that of the sludge from the IC reactor started 26 d and 58 d ago respectively.
基金Project(51275542) supported by the National Natural Science Foundation of Chinaproject(CDJXS12110010) supported by the Fundamental Research Funds for the Central Universities of China
文摘Based on the working principle and the damping characteristic of hydraulic shock absorber, a fluid structure interaction method was presented, which was used to analyze the microcosmic and high-frequency processing mechanism of fluid structure interaction between circulation valve and liquid of hydraulic shock absorber. The fluid mesh distortion was controlled by the CEL language, and the fluid struc^tre interaction mathematical model was established. The finite element model was established by ANSYS CFX software and was analyzed by dynamic mesh technique. The local sensitive computational area was meshed by prismatic grid, which could reduce the negative volume problem during the simulation. The circulation valve and liquid of hydraulic shock absorber were simulated and analyzed under the condition of sinusoidal inlet velocity loads. Flow characteristic and dynamics characteristic were obtained. The pressure distribution and the displacement of circulation value were obtained, and the acceleration curve of circulation valve was simulated and analyzed. The conformity of the final simulation results with the experimental datum indicates that this method is accurate and reliable to analyze the dynamics characteristic between circulation valve and liquid of hydraulic shock absorber, which can provide a theoretical foundation for optimizing hydraulic shock absorber in the future.
文摘At airports, runway operation is the limiting factor for the overall throughput; specifically the fixed and overly conservative ICAO wake turbulence separation minima. The wake turbulence hazardous flows can dissipate quicker because of decay due to air turbulence or be transported out of the way on oncoming traffic by cross-wind, yet wake turbulence separation minima do not take into account wind conditions. Indeed, for safety reasons, most airports assume a worst-case scenario and use conservative separations; the interval between aircraft taking off or landing therefore often amounts to several minutes. However, with the aid of accurate wind data and precise measurements of wake vortex by radar sensors, more efficient intervals can be set, particularly when weather conditions are stable. Depending on traffic volume, these adjustments can generate capacity gains, which have major commercial benefits. This paper presents the use of Electronic scanning radar for detecting wake vortices. In this method, the raindrops Doppler spectrogram is used to retrieve the strength of the wake vortex. Numerical simulation are performed to establish an empirical model used during the retrieval method. This paper presents also the results obtained during the trials of the PARIS-CDG data set recorded from October 2014 to November 2015 with an X-band RADAR developed and deployed by THALES.
基金Project(51274242)supported by the National Natural Science Foundation of ChinaProject(2015CX001)supported by the Innovation-driven Plan of Central South University,China
文摘A safe,economical treatment of hazardous chromium-bearing vanadate residue(CVR)will significantly benefit the clean production of chromate-bearing salts.This study investigated recovery of sodium vanadate and sodium chromate from CVR in sodium bicarbonate solution.Results indicate that the stability of calcium vanadate and calcium chromate depends on pH and[HCO3?].CaV2O6?4H2O transforms into CaV2O6?4H2O,CaV2O6?2H2O,CaV2O6,Ca2V2O7?2H2O,and Ca5(VO4)3(OH)when pH increases from 7.51 to 12.32.Increasing pH and reducing CVR dosage improve the vanadate extraction rate,and high V2O5 and Na2Cr2O7?2H2O extraction rates are achieved in dilute NaHCO3 solution.Moreover,addition of NaOH positively contributes to the recovery of vanadate and chromate from CVR.Over 95%V2O5 and Na2Cr2O7?2H2O in CVR can be extracted from 60 g/L NaHCO3 and 30 g/L NaOH solutions at 90°C for 2 h.In order to reduce the hazardous residue containing chromate after recovery of CVR,calcium circulation is presented.Results show that more than 60%lime can be saved with fresh residue addition to remove vanadate from sodium chromate solution due to the active CaCO3.Moreover,no lime is required in removal of vanadate when the roasting residue is added.Therefore,a novel process is developed for utilization of CVR.
基金supported by the Second Stage of Brain Korea 21 Projects and Changwon National University in 2009-2010
文摘A discontinuity of magnetic circuits according to the end effect is generated in the permanent magnet linear synchronous motor （PMLSM）. Due to the unbalanced back electro-motive force （EMF） and impedance produced, unbalanced current is generated. The cireulatin8 current, which is caused by a decrease in the thrust, is generated by the unbalanced current. The optimal design of auxiliary-teeth at the end of the mover was carried out to solve the unbalance of phase by using design of experiment （DOE）, and compared with the basic model through finite element analysis （FEA）. As a result, the auxiliary-teeth model compensates for the decrease of thrust caused by the unbalanced phase. Also, this model is proven to reduce the detent force by the vibration and noise of the PMLSM and copper loss caused by the circulating current.
文摘OBJECTIVE Our previous studies demonstrated that various ingredients from the traditional Chinese medicine(TCM)for promoting blood circulation and removing blood stasis,as exemplified by cryptotanshinone and salvianolic acid B,exerted striking effects on modulating angiogenesis and vascular permeability,which suggests that they may be effective in treating vascular leak-driven diseases(e.g.tumor,cerebral cavernous malformation and diabetic retinopathy).However,the lack of reliable and advanced technologies and models sets up difficult hurdles for better understanding the role of TCM for promoting blood circulation and removing blood stasis.To this end,this study is to outline numerous cutting-edge platforms that can be utilized for exploring the function of TCM for promoting blood circulation and removing blood stasis in vascular leak-driven diseases.METHODS Two-photon laser scanning fluorescence microscopy was used to observe the interactions between neutrophils and blood vessels in a real-time manner.Dynamic flow system was employed to mimic the in vivo behaviors of neutrophils.RIP1-Tag5 spontaneous pancreatic cancer model was used to study the function of tumor blood vessels.CCM2ECKO(deletion of CCM2 in endothelial cells)mice were employed to establish the cerebral cavernous malformation(CCM)animal model.Micro-computed tomography(micro-CT)was utilized to assess the CCM lesion.Müller cell-knockout mouse model was used to study the progression of diabetic retinopathy.Vascular permeability in this model was assessed by fluorescein angiography.RESULTS The interactions between neutrophils and endothelial cells involve a series of complicated processes,including rolling,adhesion,intraluminal crawling and transmigration,which were all monitored in vivo by two-photon laser scanning fluorescence microscopy in a real-time manner.Dynamic flow system was capable of recapitulating the biological behaviors of neutrophils in vitro.Tumor vascular function in particular vascular perfusion could be assessed in the RIP1-Tag5 spontaneous pancreatic cancer model.In terms of CCM studies,specific deletion of CCM2 in endothelial cells resulted in the initiation of CCM lesion.The size and number of CCM lesions could be visualized and quantified by micro-CT.Furthermore,the Müller cell-knockout mouse model was able to precisely reflect the clinical symptoms of diabetic retinopathy.Vascular leak could be monitored at different time points using fluorescein angiography.CONCLUSION An array of high technologies and animal models can be used in investigating the occurrence and progression of multiple vascular leak-driven diseases.The pre-clinical and clinical studies of TCM for promoting blood circulation and removing blood stasis provide fundamental support for the application of the above-mentioned platforms,with the purpose of uncovering the scientific basis of TCM for promoting blood circulation and removing blood stasis.
文摘The summer and winter circulations in the South China Sea (SCS) including the surface elevation and water temperature are simulated using the model described by Cai and Li (1996) with the monthly mean wind stress and air temperature field at the 1000 mb level from the European Centre for Medium-Range Weather Forecasts as inputs. The boundary conditions at Bashi Channel and Taiwan Strait are taken from the simulation results of the Kuroshio using the same numerical model with a grid size of 0.5°×0.5° and the results of Cai and Li (1996) as boundary conditions. The computational domain for the present paper is between 100°E and 123°E and between 4.5°N and 27°N. The horizontal resolution is 0.25°×0.25° and the vertical variations of the velocity components are resolved by 6 layers The computed steady flow, temperature and elevation fields are consistent with the corresponding fields observed. In particular, the temperature and elevation fields of the South China Sea Warm Current (SCSWC) have been successfully simulated. The paths of the branch of the Kuroshio entering the South China Sea (SCSBK) through Bashi Channel in winter and summer are discussed It is found that the SCSBK flows southward to the southern SCS from the coast of the Guangdong Province. A portion of the SCSBK returns to the Bashi Channel and subdivides again in deep waters in winter with a branch flows to the south along the coast of the Philippines instead of flowing back to the Pacific In addition, our results confirm the existence of a eastward current to the northeast of Dongsha in summer with the Kuroshio as its source as suggested by Huang et al. Since the value of the eddy viscosity adopted for the simulation of the Kuroshio is on the high side, resulting in a weaker west boundary current in the western Pacific as the boundary conditions for the present simulations, some deviations from the actual situations are expected although the results are in general consistent with observations.
文摘Efficient and reliable removal of cellulose,hemicellulose and lignin,that are the major organic pollutants in the wastewater from regenerated fiber,is critically important to prevent toxicity discharge.Low-and high-pH stresses sometimes occur in the effluent treatment systems due to the use of a large amount of acid and alkaline in the pulping process.Using flat separation method to select high-yield strains from bio-contact oxidation basin,seeing configuration of the strains and doing some physiological experiments,we found that the strains contain two kinds of main bacteria,Zoogloea sp.and Pseudomona sp.We also discovered the best growing time by spectrophotometer.The best growing time is at 0～32h,the logarithmic phase is about at 12～32h,and the stable growth phase is about 32～60h.Furthermore,we concluded that the disposal ability of high-yield strain is better than the ordinary one by doing parallel experiment.Through orthogonal test we also confirmed that the best growing temperature and pH value are 29℃and 7.3 respectively.The COD removal rate is about 93% when the biomembrane is in good condition.
文摘This essay examines current-event plays( shishiju 时事剧) and their social functions in late Ming China. Drawing on awide range or primary sources and built on secondary scholarship on information history,the essay offered a complete picture of the booming,features,social functions and the decline of the current-event plays. The essay argues that many current-event plays addressed on credibility,timeliness and easy accessibility,which enabled current-event plays to play an important role in information circulation. This essay further exposes the current-event plays not only opened a forum for public discussion but also influenced public opinions greatly from literate elites to the masses in Ming China. Through analyzing current-event plays in the context of Ming society,this essay expands the realm of studying information history.
文摘Base on dynamic analysis for a Front Wheel Assist (FWA) tractor, a method of calculating and analyzing on the critical angle of steering for a FWA tractor is described in this paper. The mathematical model is also established here. The critical steering angle which is a important parameter affecting the steering performance for a FWA tractor is defined in the article.
基金Project supported by the Priority Academic Development Program of Jiangsu Higher Education Institutions, ChinaProject(CXZZ12_0680) supported by Postgraduate Innovation Foundation of Jiangsu Province, ChinaProject(12JDG082) supported by the Advanced Talent Foundation of Jiangsu University, China
文摘In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.
文摘The popularly used circulant matrix model of deconvolution is mostly heavily ill-posed or singular and it is not suitable to many blind deconvolution problems. The aperiodic matrix model can improve the condition number of deconvolution problems and its accommodation is much wider than the circulant one's. This paper discusses a comparison of the two models including their ill-posedness, the rationality of the approximation by the models, and their computational efficiency. The comparison shows that the aperiodic model is promising in the development of new restoration algorithms.
基金Project(20120023110011) supported by Doctoral Program of Higher Education of ChinaProjects(2009KH09,2009QH02) supported by the Fundamental Research Funds for the Central Universities of China
文摘A comparative study of the influence of elevated temperature on foam geopolymer using circulating fluidized bed combustion fly ash（CFA） was reported. Foam geopoymers were prepared with different amounts of foam agent and different Si O2/Al2O3 molar ratios of 3.1, 3.4, and 3.8. The mechanical, thermo-physical properties and microstructure of the foam geopolymers before and after exposure to elevated temperature of 800, 1000, and 1200 ℃ were investigated. The specimen with Si O2/Al2O3 molar ratio of 3.8 exhibits the highest compressive strength, better microstructure and dimension stability before and after firing. Carnegeite, nepheline, and zeolite crystalline phases appearing after exposure may contribute to the good post-exposure strength. Low weight foam geopolymer using CFA can increase strength and maintain higher stability as high as 1000 ℃.
文摘In this paper, a new design method for high performance octave-band stripline circulator is given. The optimum design program is given by a construction with double-Y junction aided by a section of quarter-wavelength impedance transformer. All the calculation is simpler than that given by Y. S. Wu, et al[1-7]. Typical performances of the 2-4GHz Y-junction stripline circulator are insertion loss 0.35dB (max), isolation 21dB (min), VSWR 1.25 (max). An octave low-loss and high isolation performance is demonstrated without the need of repeated design cycles.
文摘It is critical to combat tumor metastasis by eradicating disseminated tumor cells in any step during the metastasis process.After entering the blood circulation system,tumor cells are in suspension and experience considerable levels of fluid shear stress.However,the influence of hemodynamic shear stress on the survival of CTCs and the underlying mechanotransduction mechanisms remain unclear.This study shows that fluid shear stress can eliminate the majority of CTCs and the viability of suspended tumor cells depends on the stress magnitude,indicating that tumor cells can sense and respond to fluid shear stress.Mechanistically,the expression of Piezo1 but not Piezo2 is greatly upregulated in suspended tumor cells after shear stress treatment.Inhibiting/activating Piezo1 increases/decreases the viability of suspended tumor cells in shear flow,which depends on Piezo1-mediated calcium entry.These findings suggest that Piezo1 may be the major mechanosensor by which suspended tumor cells sense fluid shear stress.As the downstream effector of Piezo1,actomyosin in tumor cells is significantly activated under increasing shear stress.Its activity influences the survival of CTCs in shear flow and rescues the effects of Piezo1 on tumor cell survival,suggesting that hemodynamic shear stress regulates the survival of CTCs through Piezo1 mediated actomyosin activity.Importantly,fluid shear stress considerably up-regulates YAP/TAZ activity of suspended tumor cells and promotes their nuclear translocation in a magnitude-dependent manner.Inhibiting YAP/TAZ enhances the viability of suspended tumor cells in shear stress,while activating their activity decreases tumor cell survival,suggesting that YAP/TAZ activation promotes the apoptosis of suspended tumor cells,which is different from the findings that YAP/TAZ facilitates the survival of adherent cells to shear flow.Further,blocking the nuclear import of YAP/TAZ inactivates the sensation of suspended tumor cells to fluid shear flow and attenuates the dependence of tumor cell survival on different magnitudes of hemodynamic shear stress.The influence of Piezo1-actomyosin pathway on suspended tumor cells can be rescued by YAP/TAZ activity,suggesting that Piezo1-mediated signaling induces tumor cell apoptosis via nuclear translocation of YAP/TAZ.In addition,fluid shear stress can also activate the expressions of LATS1/2 and MST1/2 in Hippo pathway through Piezo1,which is known to inhibit YAP/TAZ activity.Silencing/activating LATS1/2 or MST1/2 inhibits/enhances the viability of CTCs under shear stress,the effects of which can be further rescued by YAP/TAZ.These findings suggest that the responses of suspended tumor cells to hemodynamic shear stress are partially mediated by Hippo signaling.After nuclear translocation,YAP/TAZ directly bind p73/PUMA,which further promotes the transcription of pro-apoptotic genes and induces the apoptosis of suspended tumor cells.In summary,these findings show that hemodynamic shear stress considerably influences the survival of CTCs in blood circulation.We have identified the calcium channel Piezo1 as a novel mechanosensor for the response of CTCs to fluid shear stress.Hemodynamic shear stress induces the apoptosis of suspended tumor cells through Piezo1-actomyosin-YAP/TAZ-p73/PUMA signaling,which is different from the mechanotranduction mechanisms for tumor cells in adherent.Therefore,this study has unveiled the novel mechanosensor of suspended CTCs in response to fluid shear stress and the subsequent mechanisms and identified Piezo1 and YAP/TAZ as the potential therapeutic targets,through which CTCs may be effectively eradicated in the vasculature to prohibit tumor metastasis.
