Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes runn...Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above.In all cases,the irrigated roofs had increased the soil moisture,reduced temperatures of both the upper and lower surfaces,reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof.The buffered temperature fluctuations were also studied via air conditioner energy consumption.There was a 28%reduction in air conditioner energy consumption and a 33%reduction in overall energy consumption between dry and irrigated plots.Values of thermal resistance or S were determined for accuracy and for this study,there was little change which is ideal.A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum.It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof.A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption.By getting a p-value<0.05,it indicates that the model is accurate for prediction and medium temperatures were statistically different.展开更多
Essential oils of pure lavender and lavender blends have been employed as potential anxiolytic aromas in aromatherapy, but a direct comparison of their effectiveness is lacking. The current study investigated the effe...Essential oils of pure lavender and lavender blends have been employed as potential anxiolytic aromas in aromatherapy, but a direct comparison of their effectiveness is lacking. The current study investigated the effects of aroma on induced anxiety in non-clinical adults, comparing pure lavender, a commercially available blend and a no aroma control. An experimental, quantitative, mixed factorial design with an opportunity sample of 60 participants was employed. Participants were randomly allocated to three equal groups, one tested in a room infused with lavender aroma, the second with the doTerra Peace<sup>®</sup> blend, and the third free from any aroma. Participants’ state anxiety scores were measured before and after a novel video-based anxiety induction procedure. Data analysis revealed that the anxiety induction was successful and that both aromas delivered small to medium-sized buffering effects compared to no aroma. The findings add to a small body of research in an area where the practice is global yet has limited scientific evaluation. Future studies utilising brain imaging and blood serum analysis to investigate the anxiolytic mechanism of aromas would be beneficial to further our understanding.展开更多
The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure chara...The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure characteristic on shift clutch engagement process was analyzed. The study results could be used to the characteristics match of the shift clutch with the hydraulic system of the high speed tracked vehicle power shift steering transmission and the performance prediction.展开更多
Juice drinks are an important commercialization alternative for lychee, a tropical and subtropical fruit. Although the lychee juice content is important when assessing the quality of a drink, there are no published me...Juice drinks are an important commercialization alternative for lychee, a tropical and subtropical fruit. Although the lychee juice content is important when assessing the quality of a drink, there are no published methods to determine it, particularly simple ones for the routine inspection of juice drinks. Lychee juice drinks contain ingredients with buffering capacity including proteins and ions such as phosphate, citrate, lactate, carbonate, acetate and propionate. The relationship between their buffering capacity and lychee juice content was studied. Citric acid was added to pure lychee dilutions in distilled water containing 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% and 10% lychee juice. The pH of the dilutions was measured to obtain a linear model for the molar H+ concentration as a function of the added citric acid (g/L) amount LC = (BC-494.2)/12,031, where LC was the lychee juice content and BC was defined as the juice buffering coefficient.展开更多
The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base sol...The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base solutions. Litter was found to be a strong acid-base buffering system. Two legume species, Acacia mangium Willd and A. auriculaiformis A. Cunn, had very high litter pH values of around 6, which was 2 pH units higher than that of the soil where they grew. Litter of all other plantation species had litter pH of around 4, similar to that of the soil. Both legume species have high potential to neutralize soil acidity and the litter layer could act to shield soil against acid rain. The current stand of two legume species was estimated to be able to raise rain acidity by 0.1 to 0.4 pH units. Inorganic ions did not fully explain the pH pattern of different litter extracts, but high sodium and low nitrate partly accounted for the high pH of the two legume species. Some natural forest species had extremely low pH. As a whole, the litter of the natural climax forest was the driving force of soil acidification. Although plant residues are strong acid-base buffering system and able to adjust acidity of environment, only a few species can be expected to make soil more acid or alkaline through this mechanism since most species have litter pH values similar to those of soil where they grow.展开更多
The effects of soil solid components on soil sensitivity to acid deposition by sequential extraction method were studied. A multiple regression equation of soil sensitivity was set up on the basis of stepwise regressi...The effects of soil solid components on soil sensitivity to acid deposition by sequential extraction method were studied. A multiple regression equation of soil sensitivity was set up on the basis of stepwise regression analysis. The results showed that organic matter expressed dual effects that were decided by soil original pH value and exchangeable cation composition on acid buffering reactions. The hydrolysis of activated oxides was a very important proton buffering reaction when in low pH situation. The crystalline oxides also played a role in the buffering reactions, but the role was restricted by the rate of activation of oxides. Meanwhile, the results by stepwise analysis showed that factors that had significant effect on soil acid buffering capacity were content of montmorillite, soil original pH value, Al 0, Mn 0 and CEC in decreasing order. Finally, sixteen soils were classified into four types of sensitive with single index cluster and multiple fuzzy cluster analysis respectively.展开更多
Among the many strategies to fabricate the silicon/carbon composite,yolk/double-shells structure can be regarded as an effective strategy to overcome the intrinsic defects of Si-based anode materials for Li-ion batter...Among the many strategies to fabricate the silicon/carbon composite,yolk/double-shells structure can be regarded as an effective strategy to overcome the intrinsic defects of Si-based anode materials for Li-ion batteries(LIBs).Hereon,a facile and inexpensive technology to prepare silicon/carbon composite with yolk/double-shells structure is proposed,in which the double buffering carbon shells are fabricated.The silicon/carbon nanoparticles with core-shell structure are encapsulated by SiO_(2)and external carbon layer,and it shows the yolk/double-shells structure via etching the SiO_(2)sacrificial layer.The multiply shells structure not only significantly improves the electrical conductivity of composite,but also effectively prevents the exposure of Si particles from the electrolyte composition.Meanwhile,the yolk/double-shells structure can provide enough space to accommodate the volume change of the electrode during charge/discharge process and avoid the pulverization of Si particles.Moreover,the as-prepared YDS-Si/C shows excellent performance as anode of LIBs,the reversible capacity is as high as 1066 mA h g^(-1) at the current density of 0.5 A g^(-1) after 200 cycles.At the same time,the YDS-Si/C has high capacity retention and good cyclic stability.Therefore,the unique architecture design of yolk/double-shells for Si/C composite provides an instructive exploration for the development of next generation anode materials of LIBs with high electrochemical performances and structural stability.展开更多
Compared with wheeled or tracked robots,legged robots exhibit advantages on agile locomotion and higher survival chance for deadly impacts. A buffering strategy is proposed for quadruped robots with non-extreme initia...Compared with wheeled or tracked robots,legged robots exhibit advantages on agile locomotion and higher survival chance for deadly impacts. A buffering strategy is proposed for quadruped robots with non-extreme initial attitudes from the end of air-righting to the steady standing on the ground.This approach consists of landing phase,buffering phase and recovering phase. The variable stiffness control,proportional-derivative( PD) force control and foot trajectory planning are applied to the joints of quadruped robots until the end of the recovering phase. The PD parameters are tuned according to the desired performance of each phase. The above approach is verified on a virtual platform.展开更多
The structure and working principle of a hydraulic buffering valve for a power-shift transmission ZF-4WG308 were studied comprehensively, and a model of the hydraulic buffering valve was developed with AMESim. A bench...The structure and working principle of a hydraulic buffering valve for a power-shift transmission ZF-4WG308 were studied comprehensively, and a model of the hydraulic buffering valve was developed with AMESim. A bench test was conducted on a buffering valve for transmissions(ZF-4WG308) and the test results agree well with the simulated results. Further more, the influences of the key parameters of the valve on the buffering performance were also studied in details.展开更多
The latest view suggests the inactive core,surface pulverization,and poly sulfide shuttling effect of metal sulfides are responsible for their low capacity and poor cycling performance in sodium-ion batteries(SIBs).Wh...The latest view suggests the inactive core,surface pulverization,and poly sulfide shuttling effect of metal sulfides are responsible for their low capacity and poor cycling performance in sodium-ion batteries(SIBs).Whereas overcoming the above problems based on conventional nanoengineering is not efficient enough.In this work,erythrocyte-like CuS microspheres with an elastic buffering layer of ultrathin poly aniline(PANI) were synthesized through one-step selfassembly growth,followed by in situ polymerization of aniline.When CuS@PANI is used as anode electrode in SIBs,it delivers high capacity,ultrahigh rate capability(500 mAh gat 0.1 A g,and 214.5 mAh gat 40 A g),and superior cycling life of over 7500 cycles at 20 A g.A series of in/ex situ characterization techniques were applied to investigate the structural evolution and sodium-ion storage mechanism.The PANI swollen with electrolyte can stabilize solid electrolyte interface layer,benefit the ion transport/charge transfer at the PANI/electrolyte interface,and restrain the size growth of Cu particles in confined space.Moreover,finite element analyses and density functional simulations confirm that the PANI film effectively buffers the volume expansion,suppresses the surface pulverization,and traps the poly sulfide.展开更多
In this paper, the efficiencies of two production lines, one is with commonly, the other is with separately buffer capacities are compared, the result is that the former one is better than the latter
Soil samples from several forest areas in China were analyzed by X-ray powder diffractometry after mineral separation and enrichment. The density gradient separation method with sequential extraction by acetone-methyl...Soil samples from several forest areas in China were analyzed by X-ray powder diffractometry after mineral separation and enrichment. The density gradient separation method with sequential extraction by acetone-methylene iodide mixtures was applied for the separation of fine sand fraction of soil samples. The clay fraction (【 2μm) was separated from silt fraction of soil samples prior to examination. Mineral components in some fine sand and clay samples were compared, and their weathering potentiality and buffering capacity against acidic precipitation were discussed.展开更多
This paper presents a computer model to investigate the buffering function of aluminum being in equilibrium with mineral kaolinite in acidic natural water. Factors affecting the theoretical pH values are discussed. Th...This paper presents a computer model to investigate the buffering function of aluminum being in equilibrium with mineral kaolinite in acidic natural water. Factors affecting the theoretical pH values are discussed. The model is verified by analyzing practical water samples.展开更多
Lime and coal flying ash applications could mitigate pollution from acid deposition and improve the buffering ability of two acidic soils sampled from Zhejiang Province. The results showed that soil alkalinity and aci...Lime and coal flying ash applications could mitigate pollution from acid deposition and improve the buffering ability of two acidic soils sampled from Zhejiang Province. The results showed that soil alkalinity and acidified buffering capacities (QpHs ) were significantly increased, especially for liming treatment; whereas, the amounts of SO24- adsorbed by treated soils were decreased to some degrees because net negative charges of soil oxide colloidal surfaces were increased with the decrease in soil acidity, although the soil fixation abilities for adsorbed SO24- were not reduced. These facts indicated that after the alkaline ameliorators were applied, the positive and adverse effects resulted from sulfate-type acid deposition were simultaneously existed in these soil treatments.展开更多
This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: Firs...This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: First Come First Service (FCFS)/Random Service(RS) for the set of HOL cells addressed to a given output port with different/same "age" (the waiting time at the HOL position) and Pure Random Service(PRS) for all HOL cells addressed to a given output port regardless of their "ages" while the Queue Loss (QL) transfer scheme is adopted for interaction between input and output buffers in the ATM switch fabric. The results obtained show that the C-IOB ATM switch fabric with PRS service policy and the QL transfer scheme is better than other buffering ATM switch fabrics.展开更多
The traffic buffering problems in the ethernet over synchronous digital hierarchy(EOS) are introduced and analyzed. Different solutions are also presented in detail. Synchronous DRAM(SDRAM) is used as off-chip buffer ...The traffic buffering problems in the ethernet over synchronous digital hierarchy(EOS) are introduced and analyzed. Different solutions are also presented in detail. Synchronous DRAM(SDRAM) is used as off-chip buffer to store-and-retransmission ethernet frames. A new and easy control design is introduced here. The buffer area size on chip is greatly reduced and the power dissipation is lowed at the same time.展开更多
Epilepsy is a severe neurological disorder clinically identified by hyper-excitability and/or hyper-synchrony in the cortex and other subcortical regions of the brain. To regulate such excitability and synchrony, Hodg...Epilepsy is a severe neurological disorder clinically identified by hyper-excitability and/or hyper-synchrony in the cortex and other subcortical regions of the brain. To regulate such excitability and synchrony, Hodgkin and Huxley model has been deployed with either PUFA or calcium buffering coupled with ATP modulate neurotransmitter release. We formulate and analyze a system of differential equations that describe the effects of PUFA, ATP, and calcium buffering in regulating neuronal hyper-excitability and hyper-synchrony in epileptic patients. We observed that PUFA had diverse effects on the gating variables. Specifically, there was a significant reduction in the inhibitory potency of PUFA on the m-gates which may cause a direct inhibition of the voltage-gated Na+ channels and thus reduce neuronal excitability in epileptic patients. Also, the activation of the potassium channels by PUFA directly limited the neuronal hyper-excitability, while a small change in voltage potential coupled with PUFA restraint activated the voltage dependent ion channels which aided in lowering epileptic excitability in patients. In addition, higher ATP buffer levels in the presence of PUFA caused a significant hyperpolarization which may decrease neuronal excitability while lower ATP level initiated neuron depolarization. These results clearly suggest that PUFA coupled with calcium and ATP buffering could be used to modulate neuronal excitability excessive synchrony in epileptic patients.展开更多
A new fluid bag buffer mechanism,which can provide large axial stiffness under the small displacement,is designed.The dynamic change laws of the mechanism stiffness and the internal pressure of the fluid bag are studi...A new fluid bag buffer mechanism,which can provide large axial stiffness under the small displacement,is designed.The dynamic change laws of the mechanism stiffness and the internal pressure of the fluid bag are studied when it is subjected to impact load.According to the protection performance for the flexible joint and the pressure change in the fluid bag during the impact process,the sensitivity of the geometric parameters of the fluid bag to the axial stiffness is analyzed by using the orthogonal experimental method,and the optimal parameter combination of the geometric parameters of the fluid bag under impact is obtained,leading to the displacement of the inner shell reduce by 41.4%.The results show that the internal pressure of the fluid bag is a rising process of oscillation and fluctuation.The sensitivity of the geometric parameters of the fluid bag to the displacement of the inner shell from high to low is as follows:Height H,radius r,wall thickness t,chamfer A.The correlation between the geometric parameters of the fluid bag and its internal pressure is:H is negatively correlated with the internal pressure,while the r,t,and A are positively correlated with the internal pressure.展开更多
AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotraf...AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotrafilcon A and balafilcon A) were used in the study. These lenses were incubated in phosphate-buffered saline (PBS) and borate-buffered saline (BBS) solutions adjusted by 0.8 pH increments to a pH in the range of 5.8-9.0 or in hypotonic (280 mOsmol/kg), isotonic (310 mOsmol/kg) and hypertonic (380 mOsmol/kg) PBS solutions. Polarographic method was used for measuring the Dk and lenses were stacked as 4 layers to correct the boundary effect.RESULTSDk values of all contact lenses measured in BBS solutions were more stable than those in PBS solutions. Especially the etafilcon A lens showed a relative big change compared with other types of contact lenses at the same conditions. When the osmolality of PBS solution increased from hypotonic to hypertonic, Dk of all contact lenses decreased. Variations in Dk existed depending on lens materials, etafilcon A lens was the most affected and nelfilcon A was the least affected by osmolality.CONCLUSIONFrom the result obtained, it is revealed that Dk of contact lenses is changed by the pH, osmolality, and buffering condition of tear. Thus, Dk of contact lens can be varied by the lens wearers' physiological and/or pathological conditions.展开更多
An organic macromolecule, poly(1-vinylimidazole), with an appropriate polymerization degree was proposed and mixed with water to form a novel aqueous absorbent for SO_2 capture. This aqueous solution absorbent has the...An organic macromolecule, poly(1-vinylimidazole), with an appropriate polymerization degree was proposed and mixed with water to form a novel aqueous absorbent for SO_2 capture. This aqueous solution absorbent has the advantages of simple preparation, good physicochemical properties, environment-friendliness, high ability in deep removal of SO_2, and excellent reusability. Moreover, pH-responsive behavior, pH buffering absorption mechanism, and their synergistic effect on absorption performance were revealed. The solubilities of SO_2 in the absorbent were measured in detail, and the results demonstrated excellent absorption capacity and recyclability. Then, mathematic models that describe SO_2 absorption equilibrium were established, and the corresponding parameters were estimated. More importantly, on the basis of model and experimental data, the absorption and desorption could maintain high efficiency within a wide operating region. In summary, this work provided a low-cost, efficient, and unique absorbent for SO_2 capture and verified its technical feasibility in industrial application.展开更多
文摘Two methods of irrigation,drip,and sprinkler were studied to determine the response of the Javits green roof to irrigation.The control study was dry unirrigated plots.Drip irrigation consisted of irrigation tubes running through the green roof that would water the soil throughout and sprinkler irrigation used a sprinkler system to irrigate the green roof from above.In all cases,the irrigated roofs had increased the soil moisture,reduced temperatures of both the upper and lower surfaces,reduced growing medium temperatures and reduced air temperatures above the green roof relative to the unirrigated roof.The buffered temperature fluctuations were also studied via air conditioner energy consumption.There was a 28%reduction in air conditioner energy consumption and a 33%reduction in overall energy consumption between dry and irrigated plots.Values of thermal resistance or S were determined for accuracy and for this study,there was little change which is ideal.A series of infra-red and thermal probe measurements were used to determine temperatures in the air and sedum.It was determined that the sprinkler irrigation did a better job than the drip irrigation in keeping cooler temperatures within the green roof.A Mann-Whitney U test was performed to verify the variation in moisture temperatures buffering energy consumption.By getting a p-value<0.05,it indicates that the model is accurate for prediction and medium temperatures were statistically different.
文摘Essential oils of pure lavender and lavender blends have been employed as potential anxiolytic aromas in aromatherapy, but a direct comparison of their effectiveness is lacking. The current study investigated the effects of aroma on induced anxiety in non-clinical adults, comparing pure lavender, a commercially available blend and a no aroma control. An experimental, quantitative, mixed factorial design with an opportunity sample of 60 participants was employed. Participants were randomly allocated to three equal groups, one tested in a room infused with lavender aroma, the second with the doTerra Peace<sup>®</sup> blend, and the third free from any aroma. Participants’ state anxiety scores were measured before and after a novel video-based anxiety induction procedure. Data analysis revealed that the anxiety induction was successful and that both aromas delivered small to medium-sized buffering effects compared to no aroma. The findings add to a small body of research in an area where the practice is global yet has limited scientific evaluation. Future studies utilising brain imaging and blood serum analysis to investigate the anxiolytic mechanism of aromas would be beneficial to further our understanding.
文摘The dynamic math model of shift clutch in engagement process was determined on the basis of hydraulic buffering valve and shift clutch of a power shift steering transmission. The influence of buffering pressure characteristic on shift clutch engagement process was analyzed. The study results could be used to the characteristics match of the shift clutch with the hydraulic system of the high speed tracked vehicle power shift steering transmission and the performance prediction.
文摘Juice drinks are an important commercialization alternative for lychee, a tropical and subtropical fruit. Although the lychee juice content is important when assessing the quality of a drink, there are no published methods to determine it, particularly simple ones for the routine inspection of juice drinks. Lychee juice drinks contain ingredients with buffering capacity including proteins and ions such as phosphate, citrate, lactate, carbonate, acetate and propionate. The relationship between their buffering capacity and lychee juice content was studied. Citric acid was added to pure lychee dilutions in distilled water containing 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% and 10% lychee juice. The pH of the dilutions was measured to obtain a linear model for the molar H+ concentration as a function of the added citric acid (g/L) amount LC = (BC-494.2)/12,031, where LC was the lychee juice content and BC was defined as the juice buffering coefficient.
文摘The role of forest litter as an acid-base buffering system was assessed by litter from plantation and natural forests in South China. Samples were either extracted with acid solutions or titrated with acid or base solutions. Litter was found to be a strong acid-base buffering system. Two legume species, Acacia mangium Willd and A. auriculaiformis A. Cunn, had very high litter pH values of around 6, which was 2 pH units higher than that of the soil where they grew. Litter of all other plantation species had litter pH of around 4, similar to that of the soil. Both legume species have high potential to neutralize soil acidity and the litter layer could act to shield soil against acid rain. The current stand of two legume species was estimated to be able to raise rain acidity by 0.1 to 0.4 pH units. Inorganic ions did not fully explain the pH pattern of different litter extracts, but high sodium and low nitrate partly accounted for the high pH of the two legume species. Some natural forest species had extremely low pH. As a whole, the litter of the natural climax forest was the driving force of soil acidification. Although plant residues are strong acid-base buffering system and able to adjust acidity of environment, only a few species can be expected to make soil more acid or alkaline through this mechanism since most species have litter pH values similar to those of soil where they grow.
文摘The effects of soil solid components on soil sensitivity to acid deposition by sequential extraction method were studied. A multiple regression equation of soil sensitivity was set up on the basis of stepwise regression analysis. The results showed that organic matter expressed dual effects that were decided by soil original pH value and exchangeable cation composition on acid buffering reactions. The hydrolysis of activated oxides was a very important proton buffering reaction when in low pH situation. The crystalline oxides also played a role in the buffering reactions, but the role was restricted by the rate of activation of oxides. Meanwhile, the results by stepwise analysis showed that factors that had significant effect on soil acid buffering capacity were content of montmorillite, soil original pH value, Al 0, Mn 0 and CEC in decreasing order. Finally, sixteen soils were classified into four types of sensitive with single index cluster and multiple fuzzy cluster analysis respectively.
基金the National Natural Science Foundation of China(No.21703191)Key Project of Strategic New Industry of Hunan Province(No.2016GK4005 and No.2016GK4030)Research Innovation Project for Graduate students of Hunan Province(No.CX2017B302)。
文摘Among the many strategies to fabricate the silicon/carbon composite,yolk/double-shells structure can be regarded as an effective strategy to overcome the intrinsic defects of Si-based anode materials for Li-ion batteries(LIBs).Hereon,a facile and inexpensive technology to prepare silicon/carbon composite with yolk/double-shells structure is proposed,in which the double buffering carbon shells are fabricated.The silicon/carbon nanoparticles with core-shell structure are encapsulated by SiO_(2)and external carbon layer,and it shows the yolk/double-shells structure via etching the SiO_(2)sacrificial layer.The multiply shells structure not only significantly improves the electrical conductivity of composite,but also effectively prevents the exposure of Si particles from the electrolyte composition.Meanwhile,the yolk/double-shells structure can provide enough space to accommodate the volume change of the electrode during charge/discharge process and avoid the pulverization of Si particles.Moreover,the as-prepared YDS-Si/C shows excellent performance as anode of LIBs,the reversible capacity is as high as 1066 mA h g^(-1) at the current density of 0.5 A g^(-1) after 200 cycles.At the same time,the YDS-Si/C has high capacity retention and good cyclic stability.Therefore,the unique architecture design of yolk/double-shells for Si/C composite provides an instructive exploration for the development of next generation anode materials of LIBs with high electrochemical performances and structural stability.
基金Supported by the National High Technology Research and Development Program of China(No.2015AA042201)the National Natural Science Foundation of China(No.61233014,61305130)+1 种基金the Shandong Provincial Natural Science Foundation(No.ZR2013FQ003,ZR2013EEM027)China Postdoctoral Science Foundation(No.2013M541912)
文摘Compared with wheeled or tracked robots,legged robots exhibit advantages on agile locomotion and higher survival chance for deadly impacts. A buffering strategy is proposed for quadruped robots with non-extreme initial attitudes from the end of air-righting to the steady standing on the ground.This approach consists of landing phase,buffering phase and recovering phase. The variable stiffness control,proportional-derivative( PD) force control and foot trajectory planning are applied to the joints of quadruped robots until the end of the recovering phase. The PD parameters are tuned according to the desired performance of each phase. The above approach is verified on a virtual platform.
基金Project(51077096)supported by the National Natural Science Foundation of ChinaProject(2012940-15-3)supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘The structure and working principle of a hydraulic buffering valve for a power-shift transmission ZF-4WG308 were studied comprehensively, and a model of the hydraulic buffering valve was developed with AMESim. A bench test was conducted on a buffering valve for transmissions(ZF-4WG308) and the test results agree well with the simulated results. Further more, the influences of the key parameters of the valve on the buffering performance were also studied in details.
基金This work was financially supported by the National Natural Science Foundation of China(NSFC.U1904190,51925207,U1910210,52161145101 and 51872277)the Natural Science Foundation for Excellent Young Scholars of Henan Province(Grant No.212300410091)+5 种基金Program for Science and Technology Innovation Talents in Universities of Henan Province(Grant No.22HASTIT005)Key Program of Henan Province for Science and Technology(222102240029)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA21000000)the National Synchrotron Radiation Laboratory(KY2060000173)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant.YLU-DNL Fund 2021002)the Fundamental Research Funds for the Central Universities(WK2060140026).
文摘The latest view suggests the inactive core,surface pulverization,and poly sulfide shuttling effect of metal sulfides are responsible for their low capacity and poor cycling performance in sodium-ion batteries(SIBs).Whereas overcoming the above problems based on conventional nanoengineering is not efficient enough.In this work,erythrocyte-like CuS microspheres with an elastic buffering layer of ultrathin poly aniline(PANI) were synthesized through one-step selfassembly growth,followed by in situ polymerization of aniline.When CuS@PANI is used as anode electrode in SIBs,it delivers high capacity,ultrahigh rate capability(500 mAh gat 0.1 A g,and 214.5 mAh gat 40 A g),and superior cycling life of over 7500 cycles at 20 A g.A series of in/ex situ characterization techniques were applied to investigate the structural evolution and sodium-ion storage mechanism.The PANI swollen with electrolyte can stabilize solid electrolyte interface layer,benefit the ion transport/charge transfer at the PANI/electrolyte interface,and restrain the size growth of Cu particles in confined space.Moreover,finite element analyses and density functional simulations confirm that the PANI film effectively buffers the volume expansion,suppresses the surface pulverization,and traps the poly sulfide.
文摘In this paper, the efficiencies of two production lines, one is with commonly, the other is with separately buffer capacities are compared, the result is that the former one is better than the latter
文摘Soil samples from several forest areas in China were analyzed by X-ray powder diffractometry after mineral separation and enrichment. The density gradient separation method with sequential extraction by acetone-methylene iodide mixtures was applied for the separation of fine sand fraction of soil samples. The clay fraction (【 2μm) was separated from silt fraction of soil samples prior to examination. Mineral components in some fine sand and clay samples were compared, and their weathering potentiality and buffering capacity against acidic precipitation were discussed.
文摘This paper presents a computer model to investigate the buffering function of aluminum being in equilibrium with mineral kaolinite in acidic natural water. Factors affecting the theoretical pH values are discussed. The model is verified by analyzing practical water samples.
文摘Lime and coal flying ash applications could mitigate pollution from acid deposition and improve the buffering ability of two acidic soils sampled from Zhejiang Province. The results showed that soil alkalinity and acidified buffering capacities (QpHs ) were significantly increased, especially for liming treatment; whereas, the amounts of SO24- adsorbed by treated soils were decreased to some degrees because net negative charges of soil oxide colloidal surfaces were increased with the decrease in soil acidity, although the soil fixation abilities for adsorbed SO24- were not reduced. These facts indicated that after the alkaline ameliorators were applied, the positive and adverse effects resulted from sulfate-type acid deposition were simultaneously existed in these soil treatments.
文摘This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: First Come First Service (FCFS)/Random Service(RS) for the set of HOL cells addressed to a given output port with different/same "age" (the waiting time at the HOL position) and Pure Random Service(PRS) for all HOL cells addressed to a given output port regardless of their "ages" while the Queue Loss (QL) transfer scheme is adopted for interaction between input and output buffers in the ATM switch fabric. The results obtained show that the C-IOB ATM switch fabric with PRS service policy and the QL transfer scheme is better than other buffering ATM switch fabrics.
文摘The traffic buffering problems in the ethernet over synchronous digital hierarchy(EOS) are introduced and analyzed. Different solutions are also presented in detail. Synchronous DRAM(SDRAM) is used as off-chip buffer to store-and-retransmission ethernet frames. A new and easy control design is introduced here. The buffer area size on chip is greatly reduced and the power dissipation is lowed at the same time.
文摘Epilepsy is a severe neurological disorder clinically identified by hyper-excitability and/or hyper-synchrony in the cortex and other subcortical regions of the brain. To regulate such excitability and synchrony, Hodgkin and Huxley model has been deployed with either PUFA or calcium buffering coupled with ATP modulate neurotransmitter release. We formulate and analyze a system of differential equations that describe the effects of PUFA, ATP, and calcium buffering in regulating neuronal hyper-excitability and hyper-synchrony in epileptic patients. We observed that PUFA had diverse effects on the gating variables. Specifically, there was a significant reduction in the inhibitory potency of PUFA on the m-gates which may cause a direct inhibition of the voltage-gated Na+ channels and thus reduce neuronal excitability in epileptic patients. Also, the activation of the potassium channels by PUFA directly limited the neuronal hyper-excitability, while a small change in voltage potential coupled with PUFA restraint activated the voltage dependent ion channels which aided in lowering epileptic excitability in patients. In addition, higher ATP buffer levels in the presence of PUFA caused a significant hyperpolarization which may decrease neuronal excitability while lower ATP level initiated neuron depolarization. These results clearly suggest that PUFA coupled with calcium and ATP buffering could be used to modulate neuronal excitability excessive synchrony in epileptic patients.
基金supported by the Fun⁃damental Scientific Research Business Expenses of Central Universities(No.NJ2020024).
文摘A new fluid bag buffer mechanism,which can provide large axial stiffness under the small displacement,is designed.The dynamic change laws of the mechanism stiffness and the internal pressure of the fluid bag are studied when it is subjected to impact load.According to the protection performance for the flexible joint and the pressure change in the fluid bag during the impact process,the sensitivity of the geometric parameters of the fluid bag to the axial stiffness is analyzed by using the orthogonal experimental method,and the optimal parameter combination of the geometric parameters of the fluid bag under impact is obtained,leading to the displacement of the inner shell reduce by 41.4%.The results show that the internal pressure of the fluid bag is a rising process of oscillation and fluctuation.The sensitivity of the geometric parameters of the fluid bag to the displacement of the inner shell from high to low is as follows:Height H,radius r,wall thickness t,chamfer A.The correlation between the geometric parameters of the fluid bag and its internal pressure is:H is negatively correlated with the internal pressure,while the r,t,and A are positively correlated with the internal pressure.
文摘AIMTo determine the effect of pH, osmolality, and buffering system on the oxygen permeability (Dk) of soft contact lenses.METHODSTwo hydrogel lenses (nelfilcon A and etafilcon A) and 2 silicone hydrogel lenses (lotrafilcon A and balafilcon A) were used in the study. These lenses were incubated in phosphate-buffered saline (PBS) and borate-buffered saline (BBS) solutions adjusted by 0.8 pH increments to a pH in the range of 5.8-9.0 or in hypotonic (280 mOsmol/kg), isotonic (310 mOsmol/kg) and hypertonic (380 mOsmol/kg) PBS solutions. Polarographic method was used for measuring the Dk and lenses were stacked as 4 layers to correct the boundary effect.RESULTSDk values of all contact lenses measured in BBS solutions were more stable than those in PBS solutions. Especially the etafilcon A lens showed a relative big change compared with other types of contact lenses at the same conditions. When the osmolality of PBS solution increased from hypotonic to hypertonic, Dk of all contact lenses decreased. Variations in Dk existed depending on lens materials, etafilcon A lens was the most affected and nelfilcon A was the least affected by osmolality.CONCLUSIONFrom the result obtained, it is revealed that Dk of contact lenses is changed by the pH, osmolality, and buffering condition of tear. Thus, Dk of contact lens can be varied by the lens wearers' physiological and/or pathological conditions.
基金supported by the National Key R&D Program of China (No. 2016YFC0400406)
文摘An organic macromolecule, poly(1-vinylimidazole), with an appropriate polymerization degree was proposed and mixed with water to form a novel aqueous absorbent for SO_2 capture. This aqueous solution absorbent has the advantages of simple preparation, good physicochemical properties, environment-friendliness, high ability in deep removal of SO_2, and excellent reusability. Moreover, pH-responsive behavior, pH buffering absorption mechanism, and their synergistic effect on absorption performance were revealed. The solubilities of SO_2 in the absorbent were measured in detail, and the results demonstrated excellent absorption capacity and recyclability. Then, mathematic models that describe SO_2 absorption equilibrium were established, and the corresponding parameters were estimated. More importantly, on the basis of model and experimental data, the absorption and desorption could maintain high efficiency within a wide operating region. In summary, this work provided a low-cost, efficient, and unique absorbent for SO_2 capture and verified its technical feasibility in industrial application.