One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electri...One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electrical energy. The advantage of this method is based on avoiding a battery charging system. Studies have been done on energy harvesting from sea waves, however, considering energy harvesting with random JONSWAP wave theory, then determining the optimum values of energy harvested is new. This paper does that by implementing the JONSWAP wave model, calculating produced power, and realistically showing that output power is decreased in comparison with the more simple Airy wave model. In addition, parameters of the energy harvester system are optimized using a simulated annealing algorithm, yielding increased produced power.展开更多
AIM:To establish the frequency of hyperphosphate-mia following the administration of sodium phosphate laxatives in low-risk patients. METHODS:One hundred consecutive ASAⅠ-Ⅱindividuals aged 35-74 years,who were under...AIM:To establish the frequency of hyperphosphate-mia following the administration of sodium phosphate laxatives in low-risk patients. METHODS:One hundred consecutive ASAⅠ-Ⅱindividuals aged 35-74 years,who were undergoing colonic cleansing with oral sodium phosphate(OSP) before colonoscopy were recruited for this prospective study.Exclusion criteria:congestive heart failure, chronic kidney disease,diabetes,liver cirrhosis,intestinal obstruction,decreased bowel motility,increased bowel permeability,and hyperparathyroidism.The day before colonoscopy,all the participants entered a 24-h period of diet that consisted of 4 L of clear fluids with sugar or honey and 90 mL(60 g)of OSP in two 45-mL doses,5 h apart.Serum phosphate was measured before and after the administration of the laxative. RESULTS:The main demographic data(mean±SD) were:age,58.9±8.4 years;height,163.8±8.6 cm; weight,71±13 kg;body mass index,26±4;women, 66%.Serum phosphate increased from 3.74±0.56 to 5.58±1.1 mg/dL,which surpassed the normal value (2.5-4.5 mg/dL)in 87%of the patients.The highest serum phosphate was 9.6 mg/dL.Urea and creatinine remained within normal limits.Post-treatment OSP se-rum phosphate concentration correlated inversely with glomerular filtration rate(P<0.007,R 2=0.0755),total body water(P<0.001,R 2=0.156)and weight(P< 0.013,R 2=0.0635). CONCLUSION:In low-risk,well-hydrated patients, the standard dose of OSP-laxative-induced hyperphos-phatemia is related to body weight.展开更多
We study a simplified version of a West Nile virus （WNv） model discussed by Lewis et al. （2006）, which was considered as a first approximation for the spatial spread of WNv. The basic reproduction number R0 for th...We study a simplified version of a West Nile virus （WNv） model discussed by Lewis et al. （2006）, which was considered as a first approximation for the spatial spread of WNv. The basic reproduction number R0 for the non-spatial epidemic model is defined and a threshold parameter RD for the corresponding problem with null Dirichlet boundary condition is introduced. We consider a free boundary problem with a coupled system, which describes the diffusion of birds by a PDE and the movement of mosquitoes by an ODE. The risk index R0^F（t） associated with the disease in spatial setting is represented. Sufficient conditions for the WNv to eradicate or to spread are given. The asymptotic behavior of the solution to the system when the spreading occurs is considered. It is shown that the initial number of infected populations, the diffusion rate of birds and the length of initial habitat exhibit important impacts on the vanishing or spreading of the virus. Numerical simulations are presented to illustrate the analytical results.展开更多
Flood control system risk evaluation is an effective measure for flood risk management and decisions.In order to make better flood risk decisions and thereby improve social and economic benefits,the flood control risk...Flood control system risk evaluation is an effective measure for flood risk management and decisions.In order to make better flood risk decisions and thereby improve social and economic benefits,the flood control risk evaluation index system should be built to quantify and normalize flood risk effectively and efficiently.Because the current evaluation index has the binary miscibility characteristic of fuzziness and clarity,this paper establishes a new flood control system risk evaluation method based on the theory of variable sets(VS).Through a comparison of flood control risk evaluation with variable fuzzy sets(VFS) in the same basin flood control system risk evaluation,it is revealed that the new method,i.e.,flood control risk evaluation with variable fuzzy/clear mixture sets(variable sets),will be reasonable in all cases.Finally,in one case study,i.e.,the flood control system risk evaluation of Fengman Reservoir Basin,which is located in the southeast central of Jilin Province in China,the risk evaluation levels for each county in the basin as well as the whole flood risk distribution map of the basin could be provided with the new method.This provides useful information for basin flood control planning and design.展开更多
文摘One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electrical energy. The advantage of this method is based on avoiding a battery charging system. Studies have been done on energy harvesting from sea waves, however, considering energy harvesting with random JONSWAP wave theory, then determining the optimum values of energy harvested is new. This paper does that by implementing the JONSWAP wave model, calculating produced power, and realistically showing that output power is decreased in comparison with the more simple Airy wave model. In addition, parameters of the energy harvester system are optimized using a simulated annealing algorithm, yielding increased produced power.
文摘AIM:To establish the frequency of hyperphosphate-mia following the administration of sodium phosphate laxatives in low-risk patients. METHODS:One hundred consecutive ASAⅠ-Ⅱindividuals aged 35-74 years,who were undergoing colonic cleansing with oral sodium phosphate(OSP) before colonoscopy were recruited for this prospective study.Exclusion criteria:congestive heart failure, chronic kidney disease,diabetes,liver cirrhosis,intestinal obstruction,decreased bowel motility,increased bowel permeability,and hyperparathyroidism.The day before colonoscopy,all the participants entered a 24-h period of diet that consisted of 4 L of clear fluids with sugar or honey and 90 mL(60 g)of OSP in two 45-mL doses,5 h apart.Serum phosphate was measured before and after the administration of the laxative. RESULTS:The main demographic data(mean±SD) were:age,58.9±8.4 years;height,163.8±8.6 cm; weight,71±13 kg;body mass index,26±4;women, 66%.Serum phosphate increased from 3.74±0.56 to 5.58±1.1 mg/dL,which surpassed the normal value (2.5-4.5 mg/dL)in 87%of the patients.The highest serum phosphate was 9.6 mg/dL.Urea and creatinine remained within normal limits.Post-treatment OSP se-rum phosphate concentration correlated inversely with glomerular filtration rate(P<0.007,R 2=0.0755),total body water(P<0.001,R 2=0.156)and weight(P< 0.013,R 2=0.0635). CONCLUSION:In low-risk,well-hydrated patients, the standard dose of OSP-laxative-induced hyperphos-phatemia is related to body weight.
基金supported by National Natural Science Foundation of China(Grant No.11371311)Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions(Grant No.PPZY2015B109)
文摘We study a simplified version of a West Nile virus （WNv） model discussed by Lewis et al. （2006）, which was considered as a first approximation for the spatial spread of WNv. The basic reproduction number R0 for the non-spatial epidemic model is defined and a threshold parameter RD for the corresponding problem with null Dirichlet boundary condition is introduced. We consider a free boundary problem with a coupled system, which describes the diffusion of birds by a PDE and the movement of mosquitoes by an ODE. The risk index R0^F（t） associated with the disease in spatial setting is represented. Sufficient conditions for the WNv to eradicate or to spread are given. The asymptotic behavior of the solution to the system when the spreading occurs is considered. It is shown that the initial number of infected populations, the diffusion rate of birds and the length of initial habitat exhibit important impacts on the vanishing or spreading of the virus. Numerical simulations are presented to illustrate the analytical results.
基金supported by the National Natural Science Foundation of China(Grant Nos.91547111,51379027&51409043)Natural Science Foundation of Liaoning Province(Grant No.2015020608)National Science and Technology Pillar Program during the Twelfth Five-year Plan Period(Grant No.2015BAB07B03)
文摘Flood control system risk evaluation is an effective measure for flood risk management and decisions.In order to make better flood risk decisions and thereby improve social and economic benefits,the flood control risk evaluation index system should be built to quantify and normalize flood risk effectively and efficiently.Because the current evaluation index has the binary miscibility characteristic of fuzziness and clarity,this paper establishes a new flood control system risk evaluation method based on the theory of variable sets(VS).Through a comparison of flood control risk evaluation with variable fuzzy sets(VFS) in the same basin flood control system risk evaluation,it is revealed that the new method,i.e.,flood control risk evaluation with variable fuzzy/clear mixture sets(variable sets),will be reasonable in all cases.Finally,in one case study,i.e.,the flood control system risk evaluation of Fengman Reservoir Basin,which is located in the southeast central of Jilin Province in China,the risk evaluation levels for each county in the basin as well as the whole flood risk distribution map of the basin could be provided with the new method.This provides useful information for basin flood control planning and design.
