How to achieve transmissions in an energy-efficient way in multi-hop decode and forward(DF) relay cognitive radio sensor networks(CRSNs) is important since sensor nodes in CRSNs are usually battery powered. This paper...How to achieve transmissions in an energy-efficient way in multi-hop decode and forward(DF) relay cognitive radio sensor networks(CRSNs) is important since sensor nodes in CRSNs are usually battery powered. This paper aims to maximize energy efficiency(EE) by joint optimizing sensing time and power allocation in multi-channels & multihops DF relay CRSNs under constraints on outage probability and sensing performance. First, we design a channel selection scheme for sensing according to the available probabilities of multi channels. Second, we analyze the expected throughput and energy consumption and formulate the EE problem as a concave/concave fractional program. Third, coordinate ascent and Charnes-Cooper Transformation(CCT) methods are used to transform the nonlinear fractional problem into an equivalent concave problem. Subsequently, the closed form of outage probability is derived and the convergence rate of the iterative algorithm is analyzed. Finally, simulation results show that the proposed scheme can achieve effective EE.展开更多
There were various problems in the determination of oil acid value of the national standard method, and this paper developed a low cost, simple and effective way to determine the acid value of oil and grease. Furtherm...There were various problems in the determination of oil acid value of the national standard method, and this paper developed a low cost, simple and effective way to determine the acid value of oil and grease. Furthermore, the esterification of high acid Euphorbia lathyris L. oil (ELO) with methanol could be efficiently catalyzed by hydrochloric acid to produce biodiesel, and the influencing factors such as the amount of catalyst, reaction time, reaction temperature and molar ratio of oil to methanol were also studied. Under the optimized conditions with the oil to methanol molar ratio of 1:30 and a reaction temperature of 70℃, 95.8% oil conversion was obtained within 40 min in the presence of only 2.0 wt% of catalyst. Therefore, the low-cost non-edible Euphorbia lathyris L. oil as a raw material had good potential for the synthesis of biodiesel in industry.展开更多
Two types of ordered mesoporous ZSM-5 zeolites with different mesopores were synthesized by a two-step method. First,carbonaceous SBA-15 was produced by in situ carbonization of SBA-15/P123 composite. Then the obtaine...Two types of ordered mesoporous ZSM-5 zeolites with different mesopores were synthesized by a two-step method. First,carbonaceous SBA-15 was produced by in situ carbonization of SBA-15/P123 composite. Then the obtained SBA-15/C composite was transformed into crystallized mesoporous ZSM-5 by impregnation TPAOH followed by steam-assisted crystallization. The final calcined samples synthesized with typical SBA-15/P123 precursor showed a wormlike morphology with the mean mesopore size of 4.6 nm, while samples synthesized with the addition of trimethylbenzene as swelling agent in the precursor exhibited the morphology of microsphere with the mesopore size of about 9.5 nm. Both two types of mesoporous ZSM-5 zeolites exhibited large surface area and mesopore structure. The steam-assisted crystallization(SAC) was performed with lower consumption of solvents. This two-step method may also be suitable for synthesizing other ordered mesoporous zeolites used as catalysts in some catalytic processes.展开更多
1 Introduction Withthe rapid development of the E-commerce,more consumers turn to shop online.When online shoppers search for products using keywords,the related products appear with their brief descriptions.We conduc...1 Introduction Withthe rapid development of the E-commerce,more consumers turn to shop online.When online shoppers search for products using keywords,the related products appear with their brief descriptions.We conduct a real-world survey and find that most shoppers are dissatisfied with the existing"onefit-all product descriptions"and they have to spend more time to scan detail pages.However,handcrafting the attractive product descriptions is always costly.展开更多
Radiofrequency(RF)catheter ablation has emerged as an effective alternative for the treatment of atrial fibrillation(AF),but ablation lesions will result in swelling and hematoma of local surrounding tissue,triggering...Radiofrequency(RF)catheter ablation has emerged as an effective alternative for the treatment of atrial fibrillation(AF),but ablation lesions will result in swelling and hematoma of local surrounding tissue,triggering inflammatory cell infiltration and increased release of inflammatory cytokines.Some studies have shown that the inflammatory response may be related to the early occurrence of AF.The most direct way to inhibit perioperative inflammation is to use anti-inflammatory drugs such as glucocorticoids.Here,we prepared polylactic-co-glycolic acid(PLGA)nanoparticles loaded with budesonide(BUD)and delivered them through irrigation of saline during the onset of ablation.Local high temperature promoted local rupture of PLGA nanoparticles,releasing BUD,and produced a timely and effective local myocardial anti-inflammatory effect,resulting in the reduction of acute hematoma and inflammatory cell infiltration and the enhancement of ablation effect.Nanoparticles would also infiltrate into the local myocardium and gradually release BUD ingredients to produce a continuous antiinflammatory effect in the next few days.This resulted in a decrease in the level of inflammatory cytokine IL-6 and an increase of anti-inflammatory cytokine IL-10.This study explored an extraordinary drug delivery strategy to reduce ablation-related inflammation,which may prevent early recurrence of AF.展开更多
基金supported by the National Nature Science Foundation of China. (Grant No. 61771410)
文摘How to achieve transmissions in an energy-efficient way in multi-hop decode and forward(DF) relay cognitive radio sensor networks(CRSNs) is important since sensor nodes in CRSNs are usually battery powered. This paper aims to maximize energy efficiency(EE) by joint optimizing sensing time and power allocation in multi-channels & multihops DF relay CRSNs under constraints on outage probability and sensing performance. First, we design a channel selection scheme for sensing according to the available probabilities of multi channels. Second, we analyze the expected throughput and energy consumption and formulate the EE problem as a concave/concave fractional program. Third, coordinate ascent and Charnes-Cooper Transformation(CCT) methods are used to transform the nonlinear fractional problem into an equivalent concave problem. Subsequently, the closed form of outage probability is derived and the convergence rate of the iterative algorithm is analyzed. Finally, simulation results show that the proposed scheme can achieve effective EE.
文摘There were various problems in the determination of oil acid value of the national standard method, and this paper developed a low cost, simple and effective way to determine the acid value of oil and grease. Furthermore, the esterification of high acid Euphorbia lathyris L. oil (ELO) with methanol could be efficiently catalyzed by hydrochloric acid to produce biodiesel, and the influencing factors such as the amount of catalyst, reaction time, reaction temperature and molar ratio of oil to methanol were also studied. Under the optimized conditions with the oil to methanol molar ratio of 1:30 and a reaction temperature of 70℃, 95.8% oil conversion was obtained within 40 min in the presence of only 2.0 wt% of catalyst. Therefore, the low-cost non-edible Euphorbia lathyris L. oil as a raw material had good potential for the synthesis of biodiesel in industry.
基金supported by Guizhou Science and Technology Plan Project (LH[2016]7269)the Technical Talent Support Program of Guizhou Education Department (KY[2017]093)+1 种基金Guizhou Provincial Ordinary College Innovation Team ([2014]46)the Doctor Fund Project of Anshun University (Asxybsjj201511)
文摘Two types of ordered mesoporous ZSM-5 zeolites with different mesopores were synthesized by a two-step method. First,carbonaceous SBA-15 was produced by in situ carbonization of SBA-15/P123 composite. Then the obtained SBA-15/C composite was transformed into crystallized mesoporous ZSM-5 by impregnation TPAOH followed by steam-assisted crystallization. The final calcined samples synthesized with typical SBA-15/P123 precursor showed a wormlike morphology with the mean mesopore size of 4.6 nm, while samples synthesized with the addition of trimethylbenzene as swelling agent in the precursor exhibited the morphology of microsphere with the mesopore size of about 9.5 nm. Both two types of mesoporous ZSM-5 zeolites exhibited large surface area and mesopore structure. The steam-assisted crystallization(SAC) was performed with lower consumption of solvents. This two-step method may also be suitable for synthesizing other ordered mesoporous zeolites used as catalysts in some catalytic processes.
基金supported by the National Key RD Program of China (2019QY0600)the National Science Fund for Distinguished Young Scholars (62025205)+1 种基金the National Natural Science Foundation of China (Grant Nos.62032020,61960206008,62102317,62002292)the Natural Science Basic Research Plan in Shaanxi Province of China (2020JQ-207).
文摘1 Introduction Withthe rapid development of the E-commerce,more consumers turn to shop online.When online shoppers search for products using keywords,the related products appear with their brief descriptions.We conduct a real-world survey and find that most shoppers are dissatisfied with the existing"onefit-all product descriptions"and they have to spend more time to scan detail pages.However,handcrafting the attractive product descriptions is always costly.
基金the National Natural Science Foundation of China(61875015,T2125003,82100335,81870310,and 81200194)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA16021101)the Beijing Natural Science Foundation(JQ20038 and L212010).
文摘Radiofrequency(RF)catheter ablation has emerged as an effective alternative for the treatment of atrial fibrillation(AF),but ablation lesions will result in swelling and hematoma of local surrounding tissue,triggering inflammatory cell infiltration and increased release of inflammatory cytokines.Some studies have shown that the inflammatory response may be related to the early occurrence of AF.The most direct way to inhibit perioperative inflammation is to use anti-inflammatory drugs such as glucocorticoids.Here,we prepared polylactic-co-glycolic acid(PLGA)nanoparticles loaded with budesonide(BUD)and delivered them through irrigation of saline during the onset of ablation.Local high temperature promoted local rupture of PLGA nanoparticles,releasing BUD,and produced a timely and effective local myocardial anti-inflammatory effect,resulting in the reduction of acute hematoma and inflammatory cell infiltration and the enhancement of ablation effect.Nanoparticles would also infiltrate into the local myocardium and gradually release BUD ingredients to produce a continuous antiinflammatory effect in the next few days.This resulted in a decrease in the level of inflammatory cytokine IL-6 and an increase of anti-inflammatory cytokine IL-10.This study explored an extraordinary drug delivery strategy to reduce ablation-related inflammation,which may prevent early recurrence of AF.